ABINIT, developer input variables:
List and description.
This document lists and provides the description
of the name (keywords) of the "developer" input
variables to be used in the main input file of the abinit code.
Copyright (C) 1998-2017 ABINIT group (DCA,XG,RC,YG,FJ)
Content of the file : alphabetical list of "developer" variables.
A.
B.
builtintest
C.
cgtyphf
D.
densfor_pred
densty
dmft_read_occnd
dmftctqmc_basis
E.
effmass_free
eshift
exchmix
exchn2n3d
extrapwf
F.
fermie_nest
fftalg
fftcache
G.
getgam_eig2nkq
getwfkfine
H.
I.
intxc
iomode
iprcfc
irandom
irdwfkfine
isecur
istatr
istatshft
istwfk
J.
K.
L.
lotf_classic
lotf_nitex
lotf_nneigx
lotf_version
M.
macro_uj
maxnsym
mem_test
mqgrid
N.
nbdblock
nc_xccc_gspace
nctime
nloc_alg
nloc_mem
nnsclo
nnsclohf
normpawu
npulayit
nscforder
O.
optforces
optnlxccc
ortalg
P.
papiopt
pawprt_b
pawprt_k
pawujat
pawujrad
pawujv
plowan_bandf
plowan_bandi
plowan_compute
plowan_iatom
plowan_it
plowan_lcalc
plowan_natom
plowan_nbl
plowan_nt
plowan_projcalc
plowan_realspace
prepscphon
prtbltztrp
prtcif
prtdipole
prtnest
prtposcar
Q.
R.
recefermi
recgratio
recnpath
recnrec
recptrott
recrcut
rectesteg
rectolden
S.
symmorphi
T.
tfkinfunc
tfw_toldfe
tolrde
U.
use_gemm_nonlop
use_nonscf_gkk
usedmft
useria
userib
useric
userid
userie
userra
userrb
userrc
userrd
userre
useylm
V.
W.
wfoptalg
X.
xc_denpos
xc_tb09_c
builtintest
Mnemonics: BUIT-IN TEST number
Executable: abinit
Characteristic: DEVELOP
Mentioned in topic: Control.
Rarely used: [7/907] in abinit tests, [0/136] in tuto abinit tests. Test list: {bigdft:[00],etsf_io:[00],fast:[00],libxc:[00],v1:[00],v5:[00],wannier90:[00]}.
Variable type: integer
Default is 0
When builtintest is non-zero, the input file is a special one, that runs very quickly,
and that is accompanied by a specific analysis by ABINIT, at the end of the run, against
a hard-coded value of total energy (and possibly stresses, forces ...).
The echo of the analysis is done in the STATUS file.
In particular, such built-in tests can be used to check quickly
whether ABINIT fallbacks have been connected or not (bigdft, etsf_io, libxc, wannier90).
At present, builtintest=1 ... 7 are allowed. See more information in tests/built-in/README .
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cgtyphf
Mnemonics: Conjugate Gradient TYPe used for Hartree Fock exact exchange
Executable: abinit
Characteristic: DEVELOP
Mentioned in topic: Hybrids.
Rarely used: [2/907] in abinit tests, [0/136] in tuto abinit tests. Test list: {v7:[65,66]}.
Variable type: integer
Default is 2 if usefock == 1,
0 otherwise.
Gives how is calculated Fock exact exchange contribution in the conjugate gradient,
in the SCF case.
The value 2 corresponds to calculate the Fock
exact exchange contribution each time in the conjugate gradient. The value 1 corresponds to calculate the Fock
exact exchange contribution only for the initial guess (not for the gradient direction) in the conjugate gradient
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densfor_pred
Mnemonics: DENSity and FORces PREDictor
Executable: abinit
Characteristic: DEVELOP
Mentioned in topics: SCFAlgorithms, MolecularDynamics.
Moderately used: [30/907] in abinit tests, [0/136] in tuto abinit tests. Tuto test list: {}.
Variable type: integer
Default is 6 if paral_kgb==1,
2 otherwise.
Only relevant if iscf >0
Used when iscf>0, to define:
- the way a change of density is derived from a change of atomic position,
- the way forces are corrected when the SCF cycle is not converged.
Supported values :
-
0 => density not changed (fixed charge), forces not corrected
-
1 => density not changed, forces corrected with rigid ion hypothesis (atomic charge moved with atom)
-
2 => density changed and forces corrected with rigid ion hypothesis (atomic charge moves with atom)
-
3 => density changed and forces corrected with a different implementation of the rigid ion hypothesis
-
4 => density not changed, forces corrected with the use of Harris functional formula (*)
-
5 => density changed using D. Alfe 2nd-order algorithm (**), forces not corrected
-
6 => density changed using D. Alfe 2nd-order algorithm (**) and forces corrected with the use of Harris functional formula (*)
Similar negative values are also allowed (see the meaning later), for development purposes only.
No meaning for RF calculations.
For the time being,
- densfor_pred=3 must be used with ionmov=4
and iscf=5.
- densfor_pred=4, 5 or 6 must be used when band-FFT parallelism is selected.
Otherwise, use densfor_pred=2
(*)
Note concerning the correction of forces (use of densfor_pred=1, 2, 3, 4 or 6)
:
The force on the atom located at R is corrected by the addition of the following term:
F_residual=Int[dr.V_residual.dRho_atomic/dR]
, where Rho_atomic is an atomic (spherical) density.
- When such an atomic density (Rho_atomic) is found in the pseudopotential or PAW file, it is used. If not, a gaussian density
(defined by densty parameter) is used.
- When SCF mixing is done on the density (iscf>=10), the potential residual (V_residual)
is obtained from the density residual with the first order formula
V_residual=dV/drho.Rho_residual
and uses the exchange-correlation kernel
dVxc/drho=Kxc
whose computation is time-consuming for GGA functionals.
By default (positive values of densfor_pred), the local-density part of the GGA exchange-correlation kernel is used (even for GGA, for which it seems to give a reasonable accuracy).
Using the full GGA exchange correlation kernel (so, including derivatives with respect to the gradient of the density) is always possible by giving a negative value to densfor_pred. In case of hybrid functionals, a similar correction term is added, although in the density mixing scheme, the related GGA kernel is used instead of the hybrid functional kernel.
(**)
Note concerning the use of densfor_pred=5 or 6 (density prediction)
:
The algorithm is described in
Computer Physics Communications
118
(1999) 31-33
.
It uses an atomic (spherical) density. When such an atomic density is found in the pseudopotential or PAW file, it is used. If not, a gaussian density
(defined by densty parameter) is used.
Also note that, to be efficient, this algorithm requires a minimum convergence of the SCF cycle;
Typically, vres2 (or nres2) has to be small enough (10
-4
...10
-5
).
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densty
Mnemonics: initial DENSity for each TYpe of atom
Executable: abinit
Characteristic: DEVELOP
Mentioned in topic: xc.
Moderately used: [14/907] in abinit tests, [0/136] in tuto abinit tests. Tuto test list: {}.
Variable type: real(ntypat)
Default is 0.0
Gives a rough description
of the initial GS density, for each type of atom.
This value is only used to create
the first exchange and correlation potential,
and is not used anymore afterwards.
For the time being, it corresponds to an average
radius (a.u.) of the density, and is used to generate
a gaussian density. If set to 0.0d0, an optimized value is used.
No meaning for RF calculations.
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dmft_read_occnd
Mnemonics: Dynamical Mean Fied Theory: READ OCCupations (Non Diagonal)
Executable: abinit
Characteristic: DEVELOP
Mentioned in topic: DMFT.
Rarely used: [4/907] in abinit tests, [0/136] in tuto abinit tests. Test list: {paral:[92],v6:[45],v7:[28,29]}.
Variable type: integer
Default is 0
Flag to read/write Occupations as computed in DMFT. This flag is useful
to restart a DFT+DMFT calculation with self-consistency over electronic density.
The occupations are written each time a DMFT loop is finished. So if the calculation stops
because the time limit is reached, this option offers the possibility to restart the self-consistent loop
over density at the point where it stopped (assuming a restart with the wave functions, see getwfk).
-
0=> Occupations are written but never read.
-
1=> Occupations are read from I_DMFTOCCND, where I is the root for input files.
-
2=> Occupations are read from O_DMFTOCCND, where O is the root for output files.
An alternative and more simple way to restart a DFT+DMFT calculation is to use the density file (obtained with prtden=1
or prtden=-1) and the self-energy (see dmft_rslf).
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dmftctqmc_basis
Mnemonics: Dynamical Mean Fied Theory: Continuous Time Quantum Monte Carlo BASIS
Executable: abinit
Characteristic: DEVELOP
Mentioned in topic: DMFT.
Rarely used: [3/907] in abinit tests, [0/136] in tuto abinit tests. Test list: {paral:[92],v7:[28,29]}.
Variable type: integer
Default is 1
Only relevant if dmft_solv==5
Choose the basis to perform CTQMC calculation.
-
0=> Use the local basis in the spherical harmonics basis. Can be useful if the Hamiltonian has weak off diagonal terms
and for this reason, one want to keep the original basis for simplicity and for physical insight.
-
1=> Default value, diagonalize the local Hamiltonian (but only if it is not diagonal). The best choice in general.
-
2=> Diagonalise the local correlated occupation matrix. Can lead to non diagonal Hamiltonian that
cannot be handled by CTQMC. This option should be thus avoided.
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| Complete list of input variables
effmass_free
Mnemonics: EFFective MASS for the FREE electron
Executable: abinit
Characteristic: DEVELOP
Mentioned in topic: Artificial.
Rarely used: [2/907] in abinit tests, [0/136] in tuto abinit tests. Test list: {v1:[25],v6:[31]}.
Variable type: real
Default is 1
This parameter allows to change the free electron mass, with respect to its experimental value.
The electron mass is simply changed in the Schrödinger equation.
Only for testing purposes, of course.
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eshift
Mnemonics: Energy SHIFT
Executable: abinit
Characteristic: DEVELOP, ENERGY
Mentioned in topic: SCFAlgorithms.
Rarely used: [1/907] in abinit tests, [0/136] in tuto abinit tests. Test list: {v3:[45]}.
Variable type: real
Default is 0
Only relevant if wfoptalg==3
eshift gives the shift of the energy used in the
shifted Hamiltonian squared.
The algorithm will determine eigenvalues and eigenvectors centered
on eshift.
Can be specified in Ha (the default), Ry, eV or Kelvin, since
ecut
has the
'ENERGY' characteristics.
(1 Ha=27.2113845 eV)
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exchmix
Mnemonics: EXCHange MIXing
Executable: abinit
Characteristic: DEVELOP
Mentioned in topic: xc.
Rarely used: [1/907] in abinit tests, [0/136] in tuto abinit tests. Test list: {v5:[18]}.
Variable type: real
Default is 0.25
Only relevant if useexexch == 1
exchmix allows to tune the ratio of exact exchange when
useexexch is used. The default value of 0.25 corresponds to PBE0.
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exchn2n3d
Mnemonics: EXCHange N2 and N3 Dimensions
Executable: abinit
Characteristic: DEVELOP
Mentioned in topic: TuningSpeed.
Rarely used: [1/907] in abinit tests, [0/136] in tuto abinit tests. Test list: {v4:[92]}.
Variable type: integer
Default is 0
If exchn2n3d is 1, the internal representation of the FFT arrays
in reciprocal space will be array(n1,n3,n2), where the second and
third dimensions have been switched. This is to allow to be coherent with the
exchn2n3d=4xx FFT treatment.
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extrapwf
Mnemonics: flag - EXTRAPolation of the Wave-Functions
Executable: abinit
Characteristic: DEVELOP
Mentioned in topics: TuningSpeed, MolecularDynamics.
Rarely used: [1/907] in abinit tests, [0/136] in tuto abinit tests. Test list: {v7:[09]}.
Variable type: integer
Default is 0
Only relevant if densfor_pred==5 or densfor_pred==6
This flag activates the extrapolation of wave-functions from one Molecular Dynamics (or Structural Relaxation) step to another.
The wave functions are extrapolated using 2nd-order algorithm of Arias, Payne and Joannopoulos
(PRB 45, 1538 (1992)).
Note that, when activated, this extrapolation requires non-negligible additional memory resources
as the wave functions are stored for the two previous time steps. Also, it can only be activated
if a consistent density extrapolation is activated (see densfor_pred).
ABINIT 7.10: this option is under development and might give wrong results.
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fermie_nest
Mnemonics: FERMI Energy for printing the NESTing function
Executable: abinit
Mentioned in topic: printing.
Rarely used: [1/907] in abinit tests, [0/136] in tuto abinit tests. Test list: {v6:[72]}.
Variable type: real
Default is 0
This input variable is only effective when prtnest=1. The energy is relative to the calculated fermi energy.
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fftalg
Mnemonics: Fast Fourier Transform ALGorithm
Executable: abinit
Characteristic: DEVELOP
Mentioned in topic: TuningSpeed.
Moderately used: [25/907] in abinit tests, [1/136] in tuto abinit tests. Tuto test list: {tutoparal:[dfpt_03]}.
Variable type: integer
Default is 312 if FFTW3 and usedmft==0,
401 if paral_kgb==1,
112 otherwise.
This keyword is
irrelevant
when Fast Fourier Transforms are done using
Graphics Processing Units
(GPU),
i.e. when use_gpu_cuda=1 (in that case, it is ignored).
Allows to choose the algorithm
for Fast Fourier Transforms. These have to be used
when applied to wavefunctions (routine fourwf.F90),
as well as when
applied to densities and potentials (routine fourdp.F90).
Presently, it is the concatenation of three digits,
labelled (A), (B) and (C).
The first digit (A) is to be chosen among 1, 2, 3, 4 or 5 :
-
1=> use FFT routines written by S. Goedecker.
-
2=> not available anymore
-
3=> use serial or multi-threaded FFTW3 fortran routines (
http://www.fftw.org
).
Currently implemented with fftalg=312.
-
4=> use FFT routines written by S. Goedecker, 2002 version, that will
be suited for MPI and OpenMP parallelism.
-
5=> use serial or multi-threaded MKL routines
Currently implemented with fftalg=512.
The second digit (B) is related to fourdp.f :
-
0=> only use Complex-to-complex FFT
-
1=> real-to-complex is also allowed (only coded for A==1, A==3 and A==5)
The third digit (C) is related to fourwf.f :
-
0=> no use of zero padding
-
1=> use of zero padding (only coded for A==1, A==4)
-
2=> use of zero padding, and also combines actual
FFT operations (using 2 routines from S. Goedecker)
with important pre- and post-processing
operations, in order to maximize cache data reuse.
This is very efficient for cache architectures.
(coded for A==1 and A==4, but A==4 is not yet sufficiently tested)
Internal representation as ngfft(7).
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fftcache
Mnemonics: Fast Fourier Transform CACHE size
Executable: abinit
Characteristic: DEVELOP
Mentioned in topic: TuningSpeed.
Rarely used: [1/907] in abinit tests, [0/136] in tuto abinit tests. Test list: {v6:[03]}.
Variable type: integer
Default is 16 (Comment: todo: Not yet machine-dependent)
Gives the cache size of the current
machine, in Kbytes.
Internal representation as ngfft(8).
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getgam_eig2nkq
Mnemonics: GET the GAMma phonon data EIG2NKQ from dataset
Executable: abinit
Mentioned in topics: multidtset, TDepES.
Rarely used: [2/907] in abinit tests, [0/136] in tuto abinit tests. Test list: {v6:[37,50]}.
Variable type: integer
Default is 0
Only relevant if ieig2rf != 0 and qpt != (0.0,0.0,0.0)
Relevant for second-order
eigenvalue calculations using response-functions (ieig2rf != 0), and only
for non-zero wavevectors qpt.
From the electron-phonon matrix elements at some wavevector only, it is not possible to determine the Debye-Waller contribution : one has to know also the q=Gamma electron-phonon matrix elements.
The variable getgam_eig2nkq allows to transmit the information about the second-order derivatives of the
eigenvalues for q=Gamma from the dataset where the calculation at Gamma was done, to the datasets
for other wavevectors.
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getwfkfine
Mnemonics: GET the fine grid wavefunctions from _WFK file
Executable: abinit
Mentioned in topics: multidtset, DFPT, TDepES.
Rarely used: [5/907] in abinit tests, [0/136] in tuto abinit tests. Test list: {v67mbpt:[32,33,34,35],v7:[50]}.
Variable type: integer
Default is 0
Eventually used when ndtset>0
(in the multi-dataset mode), to indicate
starting wavefunctions, as an alternative to
irdwfkfine. One should first read the
explanations given for these latter variables.
The getwfkfine variables is typically used to chain the calculations
in the multi-dataset mode, since they describe from which dataset the OUTPUT
wavefunctions are to be taken, as INPUT wavefunctions
of the present dataset.
If getwfkfine==0, no use of previously computed output
wavefunction file appended with _DSx_WFK is done.
If getwfkfine is positive, its value gives the index of the dataset
for which the output wavefunction file appended with _WFK
must be used.
If getwfkfine is -1, the output wf file with _WFK
of the previous dataset must be taken,
which is a frequently occurring case.
If getwfkfine is a negative number, it indicates the number
of datasets to go backward to find the needed wavefunction file.
In this case, if one refers to a non existent data set (prior
to the first), the wavefunctions are not initialised from
a disk file, so that it is as if getwfkfine=0 for that
initialisation.
Thanks to this rule, the use of getwfkfine -1 is rather
straightforward : except for the first wavefunctions, that
are not initialized by reading a disk file, the output
wavefunction of one dataset is input of the next one.
NOTE : a negative value of a "get" variable indicates the number of datasets to go backwards;
it is not the number to be subtracted from the current dataset to find the proper dataset.
As an example :
ndtset 3 jdtset 1 2 4 getXXX -1
refers to dataset 2 when dataset 4 is initialized.
Response-function calculation :
-
one and only one of getwfkfine or irdwfkfine MUST be non-zero
-
if getwfkfine = 1 : read ground state k -wavefunctions
from a disk file appended with _WFK , produced in a
previous ground state calculation (see the
section 4
of the abinit help file).
-
Reading the fine grid wavefunction will trigger the k-points interpolation technique of the temperature dependent
calculations.
Bethe-Salpeter calculation :
-
one and only one of getwfkfine or irdwfkfine MUST be non-zero
-
if getwfkfine = 1 : read ground state k -wavefunctions
from a disk file appended with _WFK , produced in a
previous ground state calculation (see the
section 4
of the abinit help file).
-
This variable or irdwfkfine is mandatory when bs_interp_mode == 1
This variable is experimental. In development.
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intxc
Mnemonics: INTerpolation for eXchange-Correlation
Executable: abinit
Characteristic: DEVELOP
Mentioned in topic: xc.
Moderately used: [134/907] in abinit tests, [1/136] in tuto abinit tests. Tuto test list: {tutorial:[spin_5]}.
Variable type: integer
Default is 0
-
0=> do "usual" xc quadrature on fft grid
-
1=> do higher accuracy xc quadrature using fft grid
and additional points at the centers of each cube
(doubles number of grid points)--the high accuracy version
is only valid for boxcut>=2. If boxcut < 2, the code stops.
For RF calculations only intxc=0 is allowed yet. Moreover,
the GS preparation runs (giving the density file and zero-order
wavefunctions) must be done with intxc=0
Prior to ABINITv2.3, the choice intxc=1 was favoured (it was the default),
but the continuation of the development of the code lead to prefer
the default intxc=0 . Indeed, the benefit of intxc=1 is
rather small, while making it available for all cases is a
non-negligible development effort. Other targets are prioritary...
You will notice that many automatic tests use intxc=1. Please,
do not follow this historical choice for your production runs.
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| Complete list of input variables
iomode
Mnemonics: Input-Output MODE
Executable: abinit
Characteristic: DEVELOP
Mentioned in topic: parallelism.
Moderately used: [20/907] in abinit tests, [0/136] in tuto abinit tests. Tuto test list: {}.
Variable type: integer
Default is 1 if MPI_IO and paral_kgb==1,
0 otherwise.
This option selects the format used to produce the output wavefunction files and the files containing
densities and potentials. It mainly affects the creation of the output files since several parts
of Abinit are able to read data from files independently of their format (either binary files or netcdf files).
The possible values are:
-
0 => Use standard Fortran IO (ok for sequential runs, not suitable for large parallel runs)
-
1 => Use MPI/IO routines (ok both for sequential and large parallel runs)
-
3 => Use NetCDF library to produce files according to the ETSF specification
(ok for sequential, requires netcdf4 + hdf5 + MPI-IO support for large parallel runs)
By default, Abinit produces Fortran files and uses parallel MPI-IO under the hood when these
operations cannot be implemented in terms of simple Fortran write/read statements.
For example, paral_kgb=1 uses the MPI-IO API provided by your MPI library.
In a nutshell, use the default value and make sure that your MPI library supports MPI-IO
before embarking yourself in large parallel runs (HAVE_MPI_IO should be set to 1 in ~abinit/config.h).
Many MPI libraries, nowadays, support the MPI-2 standard so it's very likely that your MPI supports
parallel IO. If you encounter problems, please ask your sysadmin to install a MPI library
with MPI-IO capabilities.
There are cases, however, in which you would like to change the default behaviour.
For example, you may want to generate WFK or DEN files in etsf-io format because you need
data in this format.
In this case, you have to use iomode==3 in the input file to override the default behaviour.
Note however that you still need parallel IO capabilities enabled in the netcdf library
if you want to produce netcdf files in parallel with paral_kgb=1 (i.e. netcdf4 + hdf5 + MPI-IO).
At present, the internal fallbacks provided by Abinit do not support netcdf4 so you
have to link against an external netcdf library that supports hdf5+MPI-IO and
is compatible with the mpif90 used to compile Abinit.
See ~abinit/doc/build/config-examples/ubu_gnu_4.9_mpich.ac for a typical configuration file.
References:
-
"Specification of an extensible and portable file format for electronic structure and crystallographic data",
X. Gonze, C.-O. Almbladh, A. Cucca, D. Caliste, C. Freysoldt, M. Marques, V. Olevano, Y. Pouillon,
M.J. Verstraete, Comput. Mat. Science 43, 1056 (2008)
-
"Sharing electronic structure and crystallographic data with ETSF_IO",
D. Caliste, Y. Pouillon, M.J. Verstraete, V. Olevano, X. Gonze,
Comput. Physics Communications 179, 748 (2008)
-
see also
http://www.etsf.eu/fileformats
.
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iprcfc
Mnemonics: Integer for PReConditioner of Force Constants
Executable: abinit
Characteristic: DEVELOP
Mentioned in topic: GeoOpt.
Rarely used: [4/907] in abinit tests, [0/136] in tuto abinit tests. Test list: {v1:[44,45,48,49]}.
Variable type: integer
Default is 0
Used when iscf>0, to define the SCF preconditioning scheme.
Potential-based preconditioning schemes for the SCF loop
are still under development.
The present parameter (force constant part)
describes the way a change of force
is derived from a change of atomic position.
Supported values :
-
0 => hessian is the identity matrix
-
1 => hessian is 0.5 times the identity matrix
-
2 => hessian is 0.25 times the identity matrix
-
-1=> hessian is twice the identity matrix
-
... (simply corresponding power of 2 times the identity matrix)
No meaning for RF calculations.
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irandom
Mnemonics: Integer for the choice of the RANDOM number generator
Executable: abinit
Characteristic: DEVELOP
Mentioned in topic: PIMD.
Rarely used: [3/907] in abinit tests, [0/136] in tuto abinit tests. Test list: {v6:[26],v7:[08],v8:[05]}.
Variable type: integer
Default is 3
For the time being, only used when imgmov=9
(Langevin Path-Integral Molecular Dynamics).
irandom defines the random number generator.
Supported values :
-
1 => "uniformrandom", delivered with ABINIT package (initially comes from numerical recipes).
-
2 => intrinsic Fortran 90 random number generator.
-
3 => "ZBQ" non-deterministic random number generator by R. Chandler and P. Northrop.
(Available at ).
irandom=3 is strongly advised when performing Molecular Dynamics restarts (avoids bias).
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irdwfkfine
Mnemonics: Integer that governs the ReaDing of the grid _WFK file on the FINE grid
Executable: abinit
Mentioned in topics: multidtset, TDepES.
Rarely used: [1/907] in abinit tests, [0/136] in tuto abinit tests. Test list: {v7:[51]}.
Variable type: integer
Default is 0
Indicates eventual starting
wavefunctions. As alternative, one can use the
input variables getwfkfine.
Ground-state calculation :
-
only irdwfkfine and getwfkfine have a meaning
-
at most one of irdwfkfine or getwfkfine can be non-zero
-
if irdwfkfine = 1 : read ground state wavefunctions
from a disk file appended with _WFK , produced in a
previous ground state fine grid calculation (see the
section 4
of the abinit help file).
Response-function calculation :
-
one and only one of irdwfkfine or getwfkfine MUST be non-zero
-
if irdwfkfine = 1 : read ground state k -wavefunctions
from a disk file appended with _WFK , produced in a
previous ground state calculation (see the
section 4
of the abinit help file).
-
Reading the fine grid wavefunction will trigger the k-points interpolation technique of the temperature dependent
calculations.
Bethe-Salpeter calculation :
-
one and only one of irdwfkfine or getwfkfine MUST be non-zero
-
if irdwfkfine = 1 : read ground state k -wavefunctions
from a disk file appended with _WFK , produced in a
previous ground state calculation (see the
section 4
of the abinit help file).
-
This variable or getwfkfine is mandatory when bs_interp_mode = 1
This variable is experimental. In development.
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| Complete list of input variables
isecur
Mnemonics: Integer for level of SECURity choice
Executable: abinit
Characteristic: DEVELOP
Mentioned in topic: SCFAlgorithms.
Rarely used: [9/907] in abinit tests, [0/136] in tuto abinit tests. Test list: {fast:[17,19],v1:[08,33,85,86,98,99],v2:[51]}.
Variable type: integer
Default is 0
In the presently used algorithms, there is a compromise
between speed and robustness, that can be tuned by
using isecur.
If isecur =0, an extrapolation of out-of-line
data is allowed, and might save one non-SCF calculation every
two line minimisation when some stability conditions
are fulfilled (since there are 2 non-SCF calculations
per line minimisation, 1 out of 4 is saved)
Using isecur=1 or higher integers will raise gradually
the threshold to make extrapolation.
Using isecur=-2 will allow to save 2 non-SCF calculations
every three line minimisation, but this can make the
algorithm unstable. Lower values of isecur allows
for more (tentative) savings. In any case, there must
be one non-SCF computation per line minimisation.
No meaning for RF calculations yet.
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| Complete list of input variables
istatr
Mnemonics: Integer for STATus file rate
Executable: abinit
Characteristic: DEVELOP, NO_MULTI
Mentioned in topic: printing.
Rarely used: [7/907] in abinit tests, [0/136] in tuto abinit tests. Test list: {fast:[00],paral:[52,53],v1:[03,51,59],v3:[45]}.
Variable type: integer
Default is 0 (Comment: Values lower than 10 may not work on some machines.)
Govern the rate of output of the status file.
This status file is written when the number of the
call to the status subroutine is equal to '
istatshft
' modulo 'istatr', so that
it is written once every 'istatr' call.
When 'istatr'=0, there is no writing of a status file (which is the default).
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| Complete list of input variables
istatshft
Mnemonics: Integer for STATus file SHiFT
Executable: abinit
Characteristic: DEVELOP, NO_MULTI
Mentioned in topic: printing.
Rarely used: [1/907] in abinit tests, [0/136] in tuto abinit tests. Test list: {v3:[45]}.
Variable type: integer
Default is 1
Govern the rate of output of the status file.
This status file is written when the number of the
call to the status
subroutine is equal to 'istatshft' modulo '
istatr
', so that
it is written once every '
istatr
' call.
There is also a writing for each of the 5 first calls,
and the 10th call.
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| Complete list of input variables
istwfk
Mnemonics: Integer for choice of STorage of WaveFunction at each k point
Executable: abinit
Mentioned in topics: k-points, TuningSpeed.
Moderately used: [225/907] in abinit tests, [41/136] in tuto abinit tests. Too many tests to report (>10).
Variable type: integer(nkpt)
Default is *0 (Comment: For RF calculations, the Default is not used : istwfk is forced to be 1 deep inside the code, for all k points. For spin-orbit calculations (nspinor=2), istwfk is also forced to be 1, for all k points.)
Control the way the
wavefunction for each k-point is stored inside ABINIT,
in reciprocal space.
For the GS calculations, in the "cg" array containing the
wavefunction coefficients, there is for each k-point
and each band, a segment cg(1:2,1:npw). The 'full' number
of plane wave is determined by ecut.
However, if the k-point coordinates are build
only from zeroes and halves (see list below),
the use of time-reversal symmetry (that connects coefficients)
has been implemented, in order to use real-to-complex
FFTs (see fftalg), and to treat explicitly only half
of the number of plane waves (this being used as 'npw').
For the RF calculations, there is not only the "cg"
array, but also the "cgq" and "cg1" arrays. For the
time-reversal symmetry to decrease the number of
plane waves of these arrays, the q vector MUST be (0 0 0).
Then, for each k point, the same rule as for the
RF can be applied.
WARNING (991018) : for the time being, the time-reversal
symmetry cannot be used in the RF calculations.
-
1=> do NOT take advantage of the time-reversal symmetry
-
2=> use time-reversal symmetry for k=( 0 0 0 )
-
3=> use time-reversal symmetry for k=(1/2 0 0 )
-
4=> use time-reversal symmetry for k=( 0 0 1/2)
-
5=> use time-reversal symmetry for k=(1/2 0 1/2)
-
6=> use time-reversal symmetry for k=( 0 1/2 0 )
-
7=> use time-reversal symmetry for k=(1/2 1/2 0 )
-
8=> use time-reversal symmetry for k=( 0 1/2 1/2)
-
9=> use time-reversal symmetry for k=(1/2 1/2 1/2)
-
0=> (preprocessed) for each k point, choose automatically
the appropriate time-reversal option when it is allowed,
and chose istwfk=1 for all the other k points.
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| Complete list of input variables
lotf_classic
Mnemonics: LOTF CLASSIC model for glue model
Executable: abinit
Characteristic: DEVELOP
Mentioned in topic: LOTF.
Rarely used: [1/907] in abinit tests, [0/136] in tuto abinit tests. Test list: {paral:[41]}.
Variable type: integer
Default is 5
Glue model used in LOTF.
For the moment it is imposed to be 5.
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| Complete list of input variables
lotf_nitex
Mnemonics: LOTF Number of ITerations
Executable: abinit
Characteristic: DEVELOP
Mentioned in topic: LOTF.
Rarely used: [1/907] in abinit tests, [0/136] in tuto abinit tests. Test list: {paral:[41]}.
Variable type: integer
Default is 10
Set the number of Molecular Dynamics iterations which are computed by LOTF.
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| Complete list of input variables
lotf_nneigx
Mnemonics: LOTF max Number of NEIGhbours
Executable: abinit
Characteristic: DEVELOP
Mentioned in topic: LOTF.
Rarely used: [1/907] in abinit tests, [0/136] in tuto abinit tests. Test list: {paral:[41]}.
Variable type: integer
Default is 5
Set the max number of Neighbours used in the LOTF method.
For the moment it is imposed to be 40.
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| Complete list of input variables
lotf_version
Mnemonics: LOTF VERSION of MD algorithm
Executable: abinit
Characteristic: DEVELOP
Mentioned in topic: LOTF.
Rarely used: [1/907] in abinit tests, [0/136] in tuto abinit tests. Test list: {paral:[41]}.
Variable type: integer
Default is 2
Set the MD algorithm in the LOTF method.
For the moment it is imposed to be 2.
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| Complete list of input variables
macro_uj
Mnemonics: MACRO variable that activates the determination of the U and J parameter (for the PAW+U calculations)
Executable: abinit
Characteristic: DEVELOP
Mentioned in topic: DFT+U.
Rarely used: [2/907] in abinit tests, [1/136] in tuto abinit tests. Test list: {tutorial:[udet_2],v5:[39]}.
Variable type: integer
Default is 0
Sets proper input values for the determination of U and J i.e.
for pawujat (first atom treated with PAW+U),
irdwfk (=1),
tolvrs (=10^(-8)),
nstep (=255),
diemix (=0.45),
atvshift (pawujat) pawujv). Do not overwrite these variables manually unless you know what you do.
-
macro_uj=1 (and nsppol=2) Standard procedure to determine U on atom pawujat through a shift of the potential on both spin channels.
-
macro_uj=1 (and nsppol=1) Non standard procedure to determine U from potential shift on atom pawujat (experimental).
-
macro_uj=2 (and nsppol=2) Non standard procedure to determine U from potential shift on atom pawujat through a shift on spin channel 1 on this atom and the response on this channel (experimental).
-
macro_uj=3 (and nsppol=2) Standard procedure to determine J from potential shift on spin channel 1 on atom pawujat and response on spin channel 2 (experimental).
Determination of U and J can be done only if the symmetry of the atomic arrangement is reduced and the atom pawujat is not connected to any other atom by symmetry relations (either input reduced symmetries manually, define concerned atom as a separate atomic species or shift concerned atom from ideal position).
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| Complete list of input variables
maxnsym
Mnemonics: MAXimum Number of SYMetries
Executable: abinit
Characteristic: DEVELOP
Mentioned in topic: crystal.
Rarely used: [1/907] in abinit tests, [0/136] in tuto abinit tests. Test list: {v5:[06]}.
Variable type: integer
Default is 384
Gives the maximum number of spatial symetries allowed in the memory.
The default value is sufficient for most applications. It might have to be increased in the case of the use of a supercell (unit cell identically repeated).
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| Complete list of input variables
mem_test
Mnemonics: MEMory TEST
Executable: abinit
Characteristic: DEVELOP
Mentioned in topic: Control.
Rarely used: [1/907] in abinit tests, [0/136] in tuto abinit tests. Test list: {paral:[29]}.
Variable type: integer
Default is 1
This variable controls the memory test done in the memana routine.
Possible values:
-
0 no test on the available memory is performed
-
1 the routine tries to allocate the estimated memory, for testing
purposes, and if a failure occurs, the routine stops.
-
2 like 1, but before stopping, the routine will provide
an estimation of the available memory.
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| Complete list of input variables
mqgrid
Mnemonics: Maximum number of Q-space GRID points for pseudopotentials
Executable: abinit
Characteristic: DEVELOP
Mentioned in topic: Planewaves.
Rarely used: [5/907] in abinit tests, [0/136] in tuto abinit tests. Test list: {v4:[62],v7:[24,25,78,79]}.
Variable type: integer
Default is 3001
Govern the size of the one-dimensional information
related to pseudopotentials, in reciprocal space :
potentials, or projector functions.
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| Complete list of input variables
nbdblock
Mnemonics: Number of BanDs in a BLOCK
Executable: abinit
Characteristic: DEVELOP
Mentioned in topic: TuningSpeed.
Rarely used: [2/907] in abinit tests, [0/136] in tuto abinit tests. Test list: {v4:[93,94]}.
Variable type: integer
Default is 1
In case of non-standard, blocked algorithms for the
optimization of the wavefunctions (that is, if
wfoptalg=4):
-
if wfoptalg=4,
nbdblock defines the number of blocks (the number of bands in the block is
then nband/nbdblock ).
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| Complete list of input variables
nc_xccc_gspace
Mnemonics: Norm-Conserving pseudopotentials - use XC Core-Correction in G-SPACE
Executable: abinit
Characteristic: DEVELOP
Mentioned in topic: Planewaves.
Rarely used: [2/907] in abinit tests, [0/136] in tuto abinit tests. Test list: {v7:[10,45]}.
Variable type: integer
Default is 0 if usepaw==0,
1 if usepaw==1,
0 otherwise.
(Comment: 0 when usepaw=0, 1 when usepaw=1)
Historically, Abinit treats the model core charge used for the non-linear core
correction in real space. Alternatively, it is possible to instruct the code to compute the core charge in G-space following the same approach used in
the PAW code. The G-space formalism is more accurate than the interpolation in real space, especially when derivatives of the model core charge are
needed, e.g. DFPT. Preliminary tests showed that the violation of the acoustic sum rule is reduced when nc_xccc_gspace==1 , especially for LDA.
It is worth stressing, however, that nc_xccc_gspace==1
should be used only in conjunction with NC pseudos whose model core charge that decays quickly in
G-space. Several NC pseudos available in the Abinit table are not optimized for the G-space formalism and users are strongly invited to perform
convergence studies with respect to ecut before using this option.
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| Complete list of input variables
nctime
Mnemonics: NetCdf TIME between output of molecular dynamics informations
Executable: abinit
Characteristic: DEVELOP
Mentioned in topic: MolecularDynamics.
Rarely used: [2/907] in abinit tests, [0/136] in tuto abinit tests. Test list: {etsf_io:[21],paral:[41]}.
Variable type: integer
Default is 0
When nctime is non-zero, the molecular dynamics information
is output in NetCDF format, every nctime time step. Here is the content of an example file :
netcdf md32.outH_moldyn1 {
dimensions:
time = UNLIMITED ; // (11 currently)
DimTensor = 6 ;
DimCoord = 3 ;
NbAtoms = 32 ;
DimVector = 3 ;
DimScalar = 1 ;
variables:
double E_pot(time) ;
E_pot:units = "hartree" ;
double E_kin(time) ;
E_kin:units = "hartree" ;
double Stress(time, DimTensor) ;
Stress:units = "hartree/Bohr^3" ;
double Position(time, DimCoord, NbAtoms) ;
Position:units = "Bohr" ;
double Celerity(time, DimCoord, NbAtoms) ;
Celerity:units = "Bohr/(atomic time unit)" ;
double PrimitiveVector1(DimVector) ;
double PrimitiveVector2(DimVector) ;
double PrimitiveVector3(DimVector) ;
double Cell_Volume(DimScalar) ;
Cell_Volume:units = "Bohr^3" ;
}
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| Complete list of input variables
nloc_alg
Mnemonics: Non LOCal ALGorithm
Executable: abinit
Characteristic: DEVELOP
Mentioned in topic: TuningSpeed.
Rarely used: [5/907] in abinit tests, [0/136] in tuto abinit tests. Test list: {v2:[37,38],v4:[20,61,62]}.
Variable type: integer
Default is 4
Allows to choose the algorithm for non-local operator application.
On super-scalar architectures, the default nloc_alg=4 is the best.
More detailed explanations:
- nloc_alg=2 : Should be efficient on vector machines. It is
indeed the fastest algorithm for the NEC, but
actual tests on Fujitsu machine did not gave better
performances than the other options.
- nloc_alg=3 : same as nloc_alg==2, but the loop order is inverted.
- nloc_alg=4 : same as nloc_alg==3, but maximal use of registers
has been coded. This should be especially efficient on
scalar and super-scalar machines. This has been confirmed by tests.
Note: internally, nloc_alg is stored in
nloalg(1)
. See also nloc_mem for the tuning of the memory used in the non-local operator application.
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| Complete list of input variables
nloc_mem
Mnemonics: Non LOCal MEMOry
Executable: abinit
Characteristic: DEVELOP
Mentioned in topic: TuningSpeed.
Rarely used: [1/907] in abinit tests, [0/136] in tuto abinit tests. Test list: {paral:[41]}.
Variable type: integer
Default is 2 if usepaw==1,
1 otherwise.
Controls the memory use for the application of the non-local operator.
More detailed explanations:
-
nloc_mem==1 : (k+G) vectors are not precomputed, in order to save memory space.
-
nloc_mem==2 : (k+G) vectors are precomputed, once per k-point.
-
nloc_mem==-1 or -2 : Negative values of
nloc_mem correspond positive ones,
where the phase precomputation has been suppressed, in order to save memory space, as an array
double precision :: ph3d(2,npw,natom)
is saved (typically half the space needed
for the wavefunctions at 1 k point - this corresponds
to the silicon case). However, the computation of phases
inside nonlop is somehow time-consuming.
Note: internally, sign(nloc_mem) is stored in
nloalg(2)
and abs(nloc_mem)-1 is stored in
nloalg(3)
. See also nloc_alg for the algorithm for the non-local operator application.
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| Complete list of input variables
nnsclo
Mnemonics: Number of Non-Self Consistent LOops
Executable: abinit
Characteristic: DEVELOP
Mentioned in topic: SCFControl.
Moderately used: [34/907] in abinit tests, [4/136] in tuto abinit tests. Tuto test list: {tutoparal:[dmft_1,dmft_2,ucrpa_1],tutorial:[positron_7]}.
Variable type: integer
Default is 0
Gives the maximum number of
non-self-consistent loops of nline line minimisations,
in the SCF case (when iscf >0). In the case iscf <=0 ,
the number of non-self-consistent loops is determined
by nstep.
The Default value of 0 -- for standard plane-wave calculations -- corresponds to make
the two first fixed potential determinations
of wavefunctions have 2 non-self consistent loops,
and the next ones to have only 1 non-self consistent loop.
The Default value of 0 -- for wavelets calculations (usewvl=1) -- corresponds to make
2 steps with 3 non-self consistent loops , 2 steps with 2 non-self consistent loops,
then the next ones with 1 non-self consistent loop.
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| Complete list of input variables
nnsclohf
Mnemonics: Number of Non-Self Consistent LOops for (Hartree)-Fock exact exchange
Executable: abinit
Characteristic: DEVELOP
Mentioned in topic: Hybrids.
Rarely used: [2/907] in abinit tests, [0/136] in tuto abinit tests. Test list: {v7:[65,66]}.
Variable type: integer
Default is 1 if usefock==1,
0 otherwise.
Gives the maximum number of loops with non-self-consistent occupied states used to calculate Fock exact exchange,
in the SCF case.
The Default value is 0 when usefock = 0.
Default value is 1 when usefock = 1 and correspond to update occupied
wavefunctions at each self-consistent loop.
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| Complete list of input variables
normpawu
Mnemonics: NORMalize atomic PAW+U projector
Executable: abinit
Characteristic: DEVELOP
Mentioned in topic: DFT+U.
Rarely used: [0/907] in abinit tests, [0/136] in tuto abinit tests.
Variable type: integer(ntypat)
Default is 0
Defines whether the atomic wave function (used as projectors in PAW+U) should be renormalized to 1
within PAW sphere.
-
normpawu=0 : leave projector
-
normpawu=1 : renormalize
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| Complete list of input variables
npulayit
Mnemonics: Number of PULAY ITerations for SC mixing
Executable: abinit
Characteristic: DEVELOP
Mentioned in topic: SCFAlgorithms.
Rarely used: [6/907] in abinit tests, [0/136] in tuto abinit tests. Test list: {v3:[47,78],v4:[07],v5:[15,20,37]}.
Variable type: integer
Default is 7
Only relevant if iscf in [7,17]
Gives the number of previous iterations involved in Pulay mixing (mixing
during electronic SC iterations).
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| Complete list of input variables
nscforder
Mnemonics: Nth - SCaling Function ORDER
Executable: abinit
Mentioned in topic: Coulomb.
Moderately used: [19/907] in abinit tests, [0/136] in tuto abinit tests. Tuto test list: {}.
Variable type: integer
Default is 16
This variable controls the order of used scaling functions when the Hartree potential is computed using the Poisson solver (see icoulomb imput variable). This variable is of seldom use since the default value is large enough. Nonetheless, possible values are 8, 14, 16, 20, 24, 30, 40, 50, 60, 100. Values greater than 20 are included in ABINIT for test purposes only.
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| Complete list of input variables
optforces
Mnemonics: OPTions for the calculation of FORCES
Executable: abinit
Characteristic: DEVELOP
Mentioned in topic: ForcesStresses.
Moderately used: [40/907] in abinit tests, [17/136] in tuto abinit tests. Too many tests to report (>10).
Variable type: integer
Default is 1 if toldff or tolrff != 0,
2 otherwise.
Allows to choose options for the calculation of forces.
-
optforces=0 : the forces are set to zero, and many steps of the
computation of forces are skipped
-
optforces=1 : calculation of forces at each SCF iteration, allowing
to use forces as criterion to stop the SCF cycles
-
optforces=2 : calculation of forces at the end of the SCF iterations
(like the stresses)
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| Complete list of input variables
optnlxccc
Mnemonics: OPTion for the calculation of Non-Linear eXchange-Correlation Core Correction
Executable: abinit
Characteristic: DEVELOP
Mentioned in topic: xc.
Rarely used: [1/907] in abinit tests, [0/136] in tuto abinit tests. Test list: {v5:[45]}.
Variable type: integer
Default is 1
Allows to choose options for the calculation of non-linear XC correction.
At present, only relevant for the FHI type of pseudopotentials, with pspcod=6 .
-
optnlxccc=1 : uses the old psp6cc.f routine, with inconsistent treatment of real-space derivatives of the core function (computed in this routine, while splined in the other parts of the code)
-
optnlxccc=2 : consistent calculation derivatives, in the psp6cc_dhr.f routine from DHamann.
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| Complete list of input variables
ortalg
Mnemonics: ORThogonalisation ALGorithm
Executable: abinit
Characteristic: DEVELOP
Mentioned in topic: TuningSpeed.
Moderately used: [11/907] in abinit tests, [0/136] in tuto abinit tests. Tuto test list: {}.
Variable type: integer
Default is -2 if wfoptalg >= 10 ,
2 otherwise.
Allows to choose the algorithm
for orthogonalisation.
Positive or zero values make two projections per
line minimisation, one before the preconditioning, one
after. This is the clean application of the band-by-band
CG gradient for finding eigenfunctions.
Negative values make only one projection per line minimisation.
The orthogonalisation step is twice faster, but the
convergence is less good. This actually calls to
a better understanding of this effect.
ortalg=0, 1 or -1 is the conventional coding.
ortalg=2 or -2 try to make better use of existing registers
on the particular machine one is running.
More demanding use of registers
is provided by ortalg=3 or -3, and so on.
The maximal value is presently 4 and -4.
Tests have shown that ortalg=2 or -2 is suitable for
use on the available platforms.
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| Complete list of input variables
papiopt
Mnemonics: PAPI OPTion
Executable: abinit
Mentioned in topic: Control.
Rarely used: [0/907] in abinit tests, [0/136] in tuto abinit tests.
Variable type: integer
Default is 0
PAPI
aims to
provide the tool designer and application engineer with a
consistent interface and methodology for use of the
performance counter hardware found in most major
microprocessors. PAPI enables software engineers to see, in
near real time, the relation between software performance and
processor events.
This option can be used only when ABINIT has been compiled with the
--enable-papi
configure option.
If papiopt=1, then PAPI counters are used instead of
the usual time() routine. All the timing output of ABINIT is
then done with PAPI values. The measurements are more accurate and
give also access to the flops of the calculation.
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| Complete list of input variables
pawprt_b
Mnemonics: PAW PRinT band
Executable: abinit
Characteristic: DEVELOP
Mentioned in topic: PAW.
Rarely used: [0/907] in abinit tests, [0/136] in tuto abinit tests.
Variable type: integer
Default is 0
Forces the output of the all-electron wavefunction for
only a single band. To be used in conjuction with:
pawprtwf=1
and
pawprt_k.
The indexing of the bands start with one for the lowest occupied band
and goes up from there.
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| Complete list of input variables
pawprt_k
Mnemonics: PAW PRinT K-point
Executable: abinit
Characteristic: DEVELOP
Mentioned in topic: PAW.
Rarely used: [0/907] in abinit tests, [0/136] in tuto abinit tests.
Variable type: integer
Default is 0
Forces the output of the all-electron wavefunction for
only a single k-point. To be used in conjuction with:
pawprtwf=1
and
pawprt_b.
The indexing follows the order in ouptput of the internal
variable
kpt
in the beginning of the run.
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| Complete list of input variables
pawujat
Mnemonics: PAW+macro_UJ, ATom number
Executable: abinit
Characteristic: DEVELOP
Mentioned in topic: DFT+U.
Rarely used: [2/907] in abinit tests, [1/136] in tuto abinit tests. Test list: {tutorial:[udet_2],v5:[39]}.
Variable type: integer
Default is 1 (Comment: i.e. the first atom treated with PAW+U.)
Determines the atom for which U (or J) should be determined. See also macro_uj.
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| Complete list of input variables
pawujrad
Mnemonics: PAW+macro_UJ, sphere RADius
Executable: abinit
Characteristic: DEVELOP
Mentioned in topic: DFT+U.
Rarely used: [2/907] in abinit tests, [1/136] in tuto abinit tests. Test list: {tutorial:[udet_2],v5:[39]}.
Variable type: real
Default is 20 a.u.
The sphere radius serves to extrapolate the U value calculated at r_paw to a larger sphere radius.
See also macro_uj.
As most projector functions are localized within r_paw to ≈80%,
20 a.u. contains ≈100% of the wavefunction and corresponds to r_paw → ∞.
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| Complete list of input variables
pawujv
Mnemonics: PAW+macro_UJ, potential shift (V)
Executable: abinit
Characteristic: DEVELOP
Mentioned in topic: DFT+U.
Rarely used: [2/907] in abinit tests, [1/136] in tuto abinit tests. Test list: {tutorial:[udet_2],v5:[39]}.
Variable type: real
Default is 0.1 eV
Amplitude of the potential shift for the determination of U (or J). See also macro_uj.
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| Complete list of input variables
plowan_bandf
Mnemonics: Projected Local Orbital WANnier functions BAND Final
Executable: abinit
Characteristic: DEVELOP
Mentioned in topic: Wannier.
Rarely used: [2/907] in abinit tests, [0/136] in tuto abinit tests. Test list: {v7:[71,72]}.
Variable type: integer
Default is 0
Gives the upper band to include in the calculation of Wannier functions
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| Complete list of input variables
plowan_bandi
Mnemonics: Projected Local Orbital WANnier functions BAND Initial
Executable: abinit
Characteristic: DEVELOP
Mentioned in topic: Wannier.
Rarely used: [2/907] in abinit tests, [0/136] in tuto abinit tests. Test list: {v7:[71,72]}.
Variable type: integer
Default is 0
Gives the lower band to include in the calculation of Wannier functions
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| Complete list of input variables
plowan_compute
Mnemonics: Projected Local Orbital WANnier functions COMPUTATION
Executable: abinit
Characteristic: DEVELOP
Mentioned in topic: Wannier.
Rarely used: [2/907] in abinit tests, [0/136] in tuto abinit tests. Test list: {v7:[71,72]}.
Variable type: integer
Default is 0
Activate computation of Projected Local Orbital Wannier functions (PLO Wannier) and corresponding band structure.
Variables plowan_bandi,
plowan_bandf,
plowan_natom,
plowan_nbl,
plowan_iatom,
plowan_lcalc,
plowan_projcalc are mandatory to precise the nature of the projections.
-
0=> Default value: do not activate calculation of PLO Wannier.
-
1=> Compute PLO Wannier and band structure
-
2=> Compute PLO Wannier and band structure. In this case, the coupling in k-space between blocks of Wannier functions belonging to different
angular momenta or atoms is removed.
Other related variables are
plowan_realspace,
plowan_nt,
plowan_it.
The implementation is not symetrized over k-point and not parallelized.
(The calculation of projections is
detailed in
Phys. Rev. B 77, 205112, (2008)
)
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| Complete list of input variables
plowan_iatom
Mnemonics: Projected Local Orbital WANnier functions, Index of ATOM
Executable: abinit
Characteristic: DEVELOP
Mentioned in topic: Wannier.
Rarely used: [2/907] in abinit tests, [0/136] in tuto abinit tests. Test list: {v7:[71,72]}.
Variable type: integer
Default is 0
Gives the indices of the plowan_natom atoms on which the projections will be done.
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| Complete list of input variables
plowan_it
Mnemonics: Projected Local Orbital WANnier functions, Index of Translation.
Executable: abinit
Characteristic: DEVELOP
Mentioned in topic: Wannier.
Rarely used: [2/907] in abinit tests, [0/136] in tuto abinit tests. Test list: {v7:[71,72]}.
Variable type: integer(3,plowan_nt)
Default is 0
Requires plowan_realspace to be greater than 0 and
plowan_nt to be greater than 0.
Precise a given set of selected real space translation by using the real space vectors basis.
These atoms are used to define Wannier functions in real space. These real space
Wannier functions are used as a basis to compute the Hamiltonian.
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| Complete list of input variables
plowan_lcalc
Mnemonics: Projected Local Orbital WANnier functions, L values to use for CALCulation
Executable: abinit
Characteristic: DEVELOP
Mentioned in topic: Wannier.
Rarely used: [2/907] in abinit tests, [0/136] in tuto abinit tests. Test list: {v7:[71,72]}.
Variable type: integer(sum(plowan_nbl))
Default is -1
Gives the plowan_nbl values of angular momenta for each atom, in the order of the atoms
as given in plowan_iatom.
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| Complete list of input variables
plowan_natom
Mnemonics: Projected Local Orbital WANnier functions, Number of ATOMs
Executable: abinit
Characteristic: DEVELOP
Mentioned in topic: Wannier.
Rarely used: [2/907] in abinit tests, [0/136] in tuto abinit tests. Test list: {v7:[71,72]}.
Variable type: integer
Default is 0
Gives the number of atoms on which the projection will be done
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| Complete list of input variables
plowan_nbl
Mnemonics: Projected Local Orbital WANnier functions, NumBer of L values
Executable: abinit
Characteristic: DEVELOP
Mentioned in topic: Wannier.
Rarely used: [2/907] in abinit tests, [0/136] in tuto abinit tests. Test list: {v7:[71,72]}.
Variable type: integer(plowan_natom)
Default is 0
Gives the total number of angular momenta (over all atoms) to compute the projections.
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| Complete list of input variables
plowan_nt
Mnemonics: Projected Local Orbital WANnier functions, Number of Translation on which the real space values of
energy are computed
Executable: abinit
Characteristic: DEVELOP
Mentioned in topic: Wannier.
Rarely used: [2/907] in abinit tests, [0/136] in tuto abinit tests. Test list: {v7:[71,72]}.
Variable type: integer
Default is 0
Requires plowan_realspace to be greater than 0.
Gives a number of selected atoms. These atoms are used to define Wannier functions in real space. These real space
Wannier functions are used as a basis to compute the Hamiltonian.
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| Complete list of input variables
plowan_projcalc
Mnemonics: Projected Local Orbital WANnier functions, PROJectors values to use for CALCulation
Executable: abinit
Characteristic: DEVELOP
Mentioned in topic: Wannier.
Rarely used: [2/907] in abinit tests, [0/136] in tuto abinit tests. Test list: {v7:[71,72]}.
Variable type: integer(sum(plowan_nbl))
Default is -1
Gives the plowan_nbl values of projectors for each atom, in the order of the atoms
as given in plowan_iatom. The index i for the projectors refers to the ith number on line
orbitals of the PAW atomic data file.
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| Complete list of input variables
plowan_realspace
Mnemonics: Projected Local Orbital WANnier functions, activate REAL SPACE calculation.
Executable: abinit
Characteristic: DEVELOP
Mentioned in topic: Wannier.
Rarely used: [2/907] in abinit tests, [0/136] in tuto abinit tests. Test list: {v7:[71,72]}.
Variable type: integer
Default is 0
Can take the following values:
-
0=> Default value: do not activate calculation of real space Wannier functions.
-
1=> Compute PLO Wannier in real space for analysis. These data can also be used in a following dataset to perform a Wannier interpolation.
-
2=> Do simple Wannier Interpolation for a given k points starting from real space Wannier function Hamiltonian
computed in a preceding dataset.
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| Complete list of input variables
prepscphon
Mnemonics: PREPare Self-Consistent PHONon calculation
Executable: abinit
Characteristic: DEVELOP
Mentioned in topic: printing.
Rarely used: [0/907] in abinit tests, [0/136] in tuto abinit tests.
Variable type: integer
Default is 0
Print PCINFO, PHFREQ, and PHVEC files, for use with self-consistent phonon runs, after a perturbation
calculation. Only prints out files for the present q-point, and there is presently no tool to symmetrize
or merge these files, so use anaddb instead (with prtscphon input variable). The abinit input
variable is destined to someday bypass the use of anaddb for scphon calculations.
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| Complete list of input variables
prtbltztrp
Mnemonics: PRinT output for BoLTZTRaP code
Executable: abinit
Characteristic: DEVELOP
Mentioned in topic: printing.
Rarely used: [2/907] in abinit tests, [0/136] in tuto abinit tests. Test list: {v6:[11],v7:[88]}.
Variable type: integer
Default is 0
Print out geometry (_BLZTRP_GEOM) and eigenenergy (_BLZTRP_EIGEN) files for the
BoltzTraP code
by Georg Madsen.
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| Complete list of input variables
prtcif
Mnemonics: PRinT Crystallographic Information File
Executable: abinit
Characteristic: DEVELOP
Mentioned in topic: printing.
Rarely used: [3/907] in abinit tests, [1/136] in tuto abinit tests. Test list: {tutorial:[fold2bloch_1],v6:[08,09]}.
Variable type: integer
Default is 0
If set to 1, a CIF file is output with the crystallographic data for the present run (cell size shape and atomic positions).
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| Complete list of input variables
prtdipole
Mnemonics: PRinT DIPOLE
Executable: abinit
Characteristic: DEVELOP
Mentioned in topic: printing.
Rarely used: [1/907] in abinit tests, [0/136] in tuto abinit tests. Test list: {v6:[06]}.
Variable type: integer
Default is 0
Print out dipole of unit cell, calculated in real space for the primitive cell only. Under development.
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| Complete list of input variables
prtnest
Mnemonics: PRinT NESTing function
Executable: abinit
Characteristic: DEVELOP
Mentioned in topic: printing.
Rarely used: [2/907] in abinit tests, [0/136] in tuto abinit tests. Test list: {v6:[72],v7:[88]}.
Variable type: integer
Default is 0
If set to 1, the nesting function for the k-point grid is printed. For the moment the path in q space for the nesting function is fixed, but will become an input as well.
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| Complete list of input variables
prtposcar
Mnemonics: PRinT POSCAR file
Executable: abinit
Characteristic: DEVELOP
Mentioned in topic: printing.
Rarely used: [1/907] in abinit tests, [0/136] in tuto abinit tests. Test list: {v7:[01]}.
Variable type: integer
Default is 0
Print out VASP-style POSCAR and FORCES files, for use with PHON or frophon codes for frozen phonon calculations.
See the associated script in ~abinit/extras/post_processing/phondisp2abi.py for further details on interfacing
with PHON, PHONOPY, etc...
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| Complete list of input variables
recefermi
Mnemonics: RECursion - initial guess of the FERMI Energy
Executable: abinit
Characteristic: DEVELOP
Mentioned in topic: Recursion.
Rarely used: [1/907] in abinit tests, [0/136] in tuto abinit tests. Test list: {v5:[75]}.
Variable type: real
Default is 0
Used in Recursion method (tfkinfunc=2).
In the first SCF calculation it fixes the initial guess for the Fermi energy.
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| Complete list of input variables
recgratio
Mnemonics: RECursion - Grid RATIO
Executable: abinit
Characteristic: DEVELOP
Mentioned in topic: Recursion.
Rarely used: [1/907] in abinit tests, [0/136] in tuto abinit tests. Test list: {v5:[75]}.
Variable type: integer
Default is 1
Used in Recursion method (tfkinfunc=2).
It represents the ratio of the two grid step: recgratio=fine_step/coarse_step and
it is bigger or equal than 1. It introduces a double-grid system which permits
to compute the electronic density on a coarse grid, using a fine grid
(defined by ngfft) in the
discretisation of the green kernel (see recptrott).
Successively the density and the recursion coefficients are interpolated on the fine grid by
FFT interpolation. Note that ngfft/recgratio=number of points of the
coarse grid has to be compatible with the parallelization parameters.
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| Complete list of input variables
recnpath
Mnemonics: RECursion - Number of point for PATH integral calculations
Executable: abinit
Characteristic: DEVELOP
Mentioned in topic: Recursion.
Rarely used: [4/907] in abinit tests, [0/136] in tuto abinit tests. Test list: {mpiio:[42],paral:[42],v5:[75,76]}.
Variable type: integer
Default is 500
Used in Recursion method (tfkinfunc=2).
Determine the number of discretisation points to compute some path
integral in the recursion method ; those path integrals are used to
compute the entropy and the eigenvalues energy. during the latest SFC
cycles.
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| Complete list of input variables
recnrec
Mnemonics: RECursion - Number of RECursions
Executable: abinit
Characteristic: DEVELOP
Mentioned in topic: Recursion.
Rarely used: [4/907] in abinit tests, [0/136] in tuto abinit tests. Test list: {mpiio:[42],paral:[42],v5:[75,76]}.
Variable type: integer
Default is 10
Used in Recursion method (tfkinfunc=2).
Determine the maximum order of recursion, that is the dimension of the
krylov space we use to compute density. If the precision set by
rectolden is reached before that order, the recursion method
automatically stops.
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| Complete list of input variables
recptrott
Mnemonics: RECursion - TROTTer parameter
Executable: abinit
Characteristic: DEVELOP
Mentioned in topic: Recursion.
Rarely used: [4/907] in abinit tests, [0/136] in tuto abinit tests. Test list: {mpiio:[42],paral:[42],v5:[75,76]}.
Variable type: integer
Default is 0
Used in Recursion method (tfkinfunc=2).
Determine the trotter parameter used to compute the exponential of the hamiltonian in the
recursion method: exp(-beta*(-Delta + V)) ~ (exp(-beta/(4*recptrott)
V) exp(-beta/(4*recptrott) Delta) exp(-beta/(4*recptrott)
V))^(2*recptrott).
If set to 0, we use recptrott = 1/2 in the above formula.
Increasing recptrott improve the accuracy of the trotter formula, but
increase the dicretisation error: it may be necessary to increase
ngfft. The discretisation error is essentially the discretisation
error of the green kernel exp((recptrott/beta*|r|^2)) on the ngfft
grid.
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| Complete list of input variables
recrcut
Mnemonics: RECursion - CUTing Radius
Executable: abinit
Characteristic: DEVELOP
Mentioned in topic: Recursion.
Rarely used: [1/907] in abinit tests, [0/136] in tuto abinit tests. Test list: {v5:[75]}.
Variable type: integer
Default is 0
Used in Recursion method (tfkinfunc=2).
Used to improve the
computational time in the case of the recursion method in a large
cell: the density at a point will be computed with taking account only of
a sphere of radius recrcut.
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| Complete list of input variables
rectesteg
Mnemonics: RECursion - TEST on Electron Gas
Executable: abinit
Characteristic: DEVELOP
Mentioned in topic: Recursion.
Rarely used: [1/907] in abinit tests, [0/136] in tuto abinit tests. Test list: {v5:[76]}.
Variable type: integer
Default is 0
Used in Recursion method (tfkinfunc=2).
It is used to test an electron gas by putting the ion potential
equal to zero.
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| Complete list of input variables
rectolden
Mnemonics: RECursion - TOLerance on the difference of electronic DENsity
Executable: abinit
Characteristic: DEVELOP
Mentioned in topic: Recursion.
Rarely used: [4/907] in abinit tests, [0/136] in tuto abinit tests. Test list: {mpiio:[42],paral:[42],v5:[75,76]}.
Variable type: real
Default is 0.0 (Comment: Default value to be changed.)
Used in Recursion method (tfkinfunc=2).
Sets a tolerance for differences of electronic density that, reached TWICE
successively, will cause one SCF cycle to stop. That electronic
density difference is computed in the infinity norm (that is, it is
computed point-by-point, and then the maximum difference is computed).
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| Complete list of input variables
symmorphi
Mnemonics: SYMMORPHIc symmetry operation selection
Executable: abinit
Characteristic: DEVELOP
Mentioned in topics: crystal, GW.
Moderately used: [13/907] in abinit tests, [3/136] in tuto abinit tests. Tuto test list: {tutoplugs:[w90_1,w90_2,w90_4]}.
Variable type: integer
Default is 1
With symmorphi=1, symmetry operations with a non-symmorphic vector are allowed.
With symmorphi=0, they are not allowed.
In the latter case, if the symmetry operations are specified in the input file, the code
will stop and print an error message if a non-symmorphic vector is encountered.
By contrast, if the symmetry operations are to be determined automatically
(if nsym=0), then the set of symmetries will
not include the non-symmorphic operations.
Note : this feature exist because in a previous status of the GW calculations, non-symmorphic
symmetry operations could not be exploited. Thus, the k points were restricted
to the IBZ. In order to prepare GW calculations, and to perform GW calculations,
symmorphi=0 was to be used, together with nsym=0.
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| Complete list of input variables
tfkinfunc
Mnemonics: Thomas-Fermi KINetic energy FUNCtional
Executable: abinit
Characteristic: DEVELOP
Mentioned in topic: Recursion.
Rarely used: [6/907] in abinit tests, [0/136] in tuto abinit tests. Test list: {mpiio:[42],paral:[42],v4:[97],v5:[75,76],v7:[11]}.
Variable type: integer
Default is 0
-
tfkinfunc=1 : Thomas-Fermi
kinetic functional (explicit functional of the density) is used instead of Kohn-Sham kinetic
energy functional (implicit functional of the density through Kohn-Sham wavefunctions).
See Perrot F., Phys. Rev. A20,586-594 (1979)).
-
tfkinfunc=11 : Thomas-Fermi-Weizsacker
kinetic functional with Gradient Corrections is used.
The convergence of a calculation with this functional needs to be initialized from a calculation without Gradient Correction.
This is automatically done with tfkinfunc=11. For the initialization steps, the tfw_toldfe criterion is used.
When it is reached, then the Gradient Correction is added and the SCF cycle continues.
Note: to obtain the convergence of a Molecular Dynamics simulation with TFW, it is necessary to find the best set of
preconditionning parameters (diemix, diemac, dielng) and the best value of npulayit (if the default Pulay mixing is used).
-
tfkinfunc=12 : same as tfkinfunc=11,
but without the initialization steps. Gradient correction is directly added.
-
tfkinfunc=2 : the Recursion Method
is used in order to compute electronic density, entropy, Fermi energy and eigenvalues energy.
This method computes the density without computing any orbital, is efficient at high temperature,
with a efficient parallelization (almost perfect scalability). When that option is in use, the
ecut input variable is no longer a convergence parameter ;
ngfft becomes the main convergence parameter: you should adapt ecut for the ngfft
grid you need (it is not yet automatically computed). Other convergence parameter are for the energetic values:
recnrec, recptrott, recnpath.
Since the convergence of the self-consistent cycle
is determined directly by the convergence of the density:
toldfe, toldff, tolrff,
tolvrs, tolwfr are not used, and are replaced by
rectolden; the energetic values, except for the fermi energy, are only
computed during the latest SFC cycle : the output file will show a
jump of the total energy at the end, but it is not because of a bad
convergence behavior. Computational speed can be improved by the use
of recrcut and recgratio.
The recursion method has not be tested in the case of non cubic cell
or with the use of symmetries.
In the recursion method the following variables are set to:
useylm=1, userec=1.
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| Complete list of input variables
tfw_toldfe
Mnemonics: Thomas-Fermi-Weizsacker: TOLerance on the DiFference of total Energy, for initialization steps
Executable: abinit
Characteristic: ENERGY
Mentioned in topic: Recursion.
Rarely used: [1/907] in abinit tests, [0/136] in tuto abinit tests. Test list: {v7:[11]}.
Variable type: real
Default is 1.0E-6 or toldfe is present
Only relevant if tfkinfunc=11
This input variable has the same definition as toldfe and is only relevant when tfkinfunc=11.
It sets a tolerance for absolute differences of total energy that, reached TWICE successively, will cause the
initialization steps (without gradient correction) to stop and the gradient correction to be added.
Can be specified in Ha (the default), Ry, eV or Kelvin, since it has the 'ENERGY' characteristics.
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| Complete list of input variables
tolrde
Mnemonics: TOLerance on the Relative Difference of Eigenenergies
Executable: abinit
Mentioned in topic: SCFControl.
Rarely used: [2/907] in abinit tests, [1/136] in tuto abinit tests. Test list: {atompaw:[04],tutoparal:[dfpt_04]}.
Variable type: real
Default is 0.005
Sets a tolerance for the ratio of differences of eigenenergies
in the line minimisation conjugate-gradient algorithm. It compares the
decrease of the eigenenergy due to the last line minimisation, with the
one observed for the first line minimisation.
When the ratio is lower than tolrde,
the next line minimisations are skipped.
The number of line minimisations is limited by
nline anyhow.
This stopping criterion is present for both GS and RF calculations.
In RF calculations, tolrde is actually doubled before comparing with the above-mentioned
ratio, for historical reasons.
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| Complete list of input variables
use_gemm_nonlop
Mnemonics: USE the GEMM routine for the application of the NON-Local OPerator
Executable: abinit
Characteristic: DEVELOP
Mentioned in topic: parallelism.
Rarely used: [2/907] in abinit tests, [0/136] in tuto abinit tests. Test list: {paral:[25,30]}.
Variable type: integer
Default is 0 (Comment: because it is not usually worth using it unless bandpp is large and it requires additional memory)
This keyword tells abinit to use a BLAS routine to speed up the computation of the non-local operator. This requires the precomputation of a large matrix, and has a significant memory overhead. In exchange, it provides improved performance when used on several bands at once (Chebyshev or LOBPCG algorithm with bandpp
The memory overhead is proportional to the number of atoms, the number of plane waves, and the number of projectors per atom. It can be mitigated by distributing the array with
npfft
The performance depends crucially on having a good BLAS installed. Provided the BLAS supports OpenMP, this option also yields very good scaling for the nonlocal operator.
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| Complete list of input variables
use_nonscf_gkk
Mnemonics: USE NON-SCF calculation of GKK matrix elements (electron phonon)
Executable: abinit
Characteristic: DEVELOP
Mentioned in topic: ElPhonInt.
Rarely used: [5/907] in abinit tests, [1/136] in tuto abinit tests. Test list: {tutorespfn:[eph_1],v5:[85],v6:[72,90],v7:[90]}.
Variable type: integer
Default is 0 (Comment: Default is 0 for the moment. Do not use non-scf method.)
When this flag is activated during a phonon calculation with abinit, all of the perturbations are cycled through, but only the symmetry-irreducible ones are calculated self-consistently. For the others the perturbed density is rotated by the appropriate symop and the gkk matrix elements are calculated non-self-consistently. As they do not depend on the perturbed wave functions, they are correct from the first iteration, and nstep is set to 1 for those perturbations. Note that the resulting 1DEN files are simply the rotate/symmetric ones and that the resulting 1WF files are garbage (completely unconverged) except the matrix elements in the header (equivalent to GKK files, but please use the latter much smaller files for el-ph calculations). The new default behavior with use_nonscf_gkk = 1 should be transparent for the user, with the same output files but a much quicker execution.
Caveat: Note that very tight convergence of ground state and phonon calculations is necessary to get good GKK matrix elements! tolwfr = 1.e-24 or so is recommended everywhere. There may be problems using use_nonscf_gkk = 1 with non-symmorphic symmetries - please check (at least) that lifetimes for phonons go to 0 for acoustic modes at Gamma.
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| Complete list of input variables
usedmft
Mnemonics: USE Dynamical Mean Field Theory
Executable: abinit
Characteristic: DEVELOP
Mentioned in topic: DMFT.
Moderately used: [21/907] in abinit tests, [1/136] in tuto abinit tests. Tuto test list: {tutoparal:[dmft_2]}.
Variable type: integer
Default is 0
If set to 1, enable the use of DFT+DMFT, see in particular the important variables
dmft_solv,
dmftbandi,
dmftbandf,
dmft_nwli,
dmft_nwlo,
dmft_tollc,
dmft_tolfreq,
and dmft_iter.
The current implementation uses Wannier functions obtained from
projected local orbitals
as correlated orbitals (see dmftbandi and dmftbandf input variables to define them).
The Green functions are computed on a mesh of linear Matsubara frequencies. However, most of the code uses logarithmic Matsubara grid to lower the computational cost. Both dmft_nwli and dmft_nwlo are thus convergence parameters.
DMFT is currently available for collinear (nspinor=1) polarized or unpolarized calculations (nspden=nsppol=2 or nspden=nsppol=1)
and for non collinear calculations (nspinor=2,nspden=4,nsppol=1). However it is not yet available
for collinear antiferromagnetic calculations (nspden=2,nsppol=1) and non collinear non magnetic calculations (nspden=1, nsppol=1,nspinor=2).
CTQMC calculations (dmft_solv=5) are not yet possible if nspinor=2.
Only static calculations without relaxation or dynamics are possible (forces and stress are not computed in the scheme: so the computed values should NOT be trusted).
When correlated density matrices are diagonal, all values of upawu and jpawu
are possible. If the correlated density matrices are non diagonal, only jpawu = 0 is implemented.
Relevant direct output quantities from
converged DMFT calculations are total energy and occupation of correlated orbitals. For Hubbard I calculation (dmft_solv=2), total and partial spectral
functions can be obtained with prtdos=1 and can be found in files OUTSpFunc* (where OUT is the root for
output files). For CTQMC calculations (dmft_solv=5), imaginary time impurity Green function are output of the calculations and can be used to produce
spectral function using an external Maximum Entropy Code.
A typical DFT+DMFT calculation involves two runs. First, a DFT calculation is fully converged (even unoccupied wavefunctions have to be converged).
Then, the DFT+DMFT calculation is started using DFT wavefunctions or density files. As DFT+DMFT calculations (with CTQMC) are computationnally
expensive, it is convenient to use prtden=-1, to write DEN file at each DFT iteration, in order to be able to restart the calculation easily.
For details of the implementation see,
B. Amadon, F. Lechermann, A. Georges, F. Jollet, T. O. Wehling, and A. I. Lichtenstein, Phys. Rev. B 77(20), (2008)
, for Wannier functions and
B. Amadon, J. Phys.: Condens. Matter 24 075604 (2012) (doi:10.1088/0953-8984/24/7/075604),
for self-consistency and Hubbard I implementation.
If usedmft=1 and nbandkss/=0, then, the DFT+DMFT calculation is not done and only projections are computed at the end
of the calculation. They can be used by an external code or used to compute the screened interaction (see variable ucrpa).
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| Complete list of input variables
useria
Mnemonics: USER Integer variable A
Executable: abinit
Mentioned in topic: Dev.
Rarely used: [0/907] in abinit tests, [0/136] in tuto abinit tests.
Variable type: integer
Default is 0
These are user-definable integers which the user may
input and then utilize in subroutines of his/her own
design. They are not used in the official versions
of the ABINIT code, and should ease independent
developments (hopefully integrated in the official
version afterwards).
Internally, they are available in the dtset structured datatype,
e.g. dtset%useria .
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| Complete list of input variables
userib
Mnemonics: USER Integer variable B
Executable: abinit
Mentioned in topic: Dev.
Rarely used: [0/907] in abinit tests, [0/136] in tuto abinit tests.
Variable type: integer
Default is 0
These are user-definable integers which the user may
input and then utilize in subroutines of his/her own
design. They are not used in the official versions
of the ABINIT code, and should ease independent
developments (hopefully integrated in the official
version afterwards).
Internally, they are available in the dtset structured datatype,
e.g. dtset%useria .
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| Complete list of input variables
useric
Mnemonics: USER Integer variable C
Executable: abinit
Mentioned in topic: Dev.
Rarely used: [0/907] in abinit tests, [0/136] in tuto abinit tests.
Variable type: integer
Default is 0
These are user-definable integers which the user may
input and then utilize in subroutines of his/her own
design. They are not used in the official versions
of the ABINIT code, and should ease independent
developments (hopefully integrated in the official
version afterwards).
Internally, they are available in the dtset structured datatype,
e.g. dtset%useria .
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userid
Mnemonics: USER Integer variable D
Executable: abinit
Mentioned in topic: Dev.
Rarely used: [0/907] in abinit tests, [0/136] in tuto abinit tests.
Variable type: integer
Default is 0
These are user-definable integers which the user may
input and then utilize in subroutines of his/her own
design. They are not used in the official versions
of the ABINIT code, and should ease independent
developments (hopefully integrated in the official
version afterwards).
Internally, they are available in the dtset structured datatype,
e.g. dtset%useria .
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userie
Mnemonics: USER Integer variable E
Executable: abinit
Mentioned in topic: Dev.
Rarely used: [0/907] in abinit tests, [0/136] in tuto abinit tests.
Variable type: integer
Default is 0
These are user-definable integers which the user may
input and then utilize in subroutines of his/her own
design. They are not used in the official versions
of the ABINIT code, and should ease independent
developments (hopefully integrated in the official
version afterwards).
Internally, they are available in the dtset structured datatype,
e.g. dtset%useria .
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userra
Mnemonics: USER Real variable A
Executable: abinit
Mentioned in topic: Dev.
Rarely used: [0/907] in abinit tests, [0/136] in tuto abinit tests.
Variable type: real
Default is 0.0
These are user-definable with the same purpose as useria and cie.
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userrb
Mnemonics: USER Real variable B
Executable: abinit
Mentioned in topic: Dev.
Rarely used: [0/907] in abinit tests, [0/136] in tuto abinit tests.
Variable type: real
Default is 0.0
These are user-definable with the same purpose as useria and cie.
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userrc
Mnemonics: USER Real variable C
Executable: abinit
Mentioned in topic: Dev.
Rarely used: [0/907] in abinit tests, [0/136] in tuto abinit tests.
Variable type: real
Default is 0.0
These are user-definable with the same purpose as useria and cie.
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userrd
Mnemonics: USER Real variable D
Executable: abinit
Mentioned in topic: Dev.
Rarely used: [0/907] in abinit tests, [0/136] in tuto abinit tests.
Variable type: real
Default is 0.0
These are user-definable with the same purpose as useria and cie.
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userre
Mnemonics: USER Real variable E
Executable: abinit
Mentioned in topic: Dev.
Rarely used: [0/907] in abinit tests, [0/136] in tuto abinit tests.
Variable type: real
Default is 0.0
These are user-definable with the same purpose as useria and cie.
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useylm
Mnemonics: USE YLM (the spherical harmonics)
Executable: abinit
Characteristic: DEVELOP
Mentioned in topic: TuningSpeed.
Rarely used: [6/907] in abinit tests, [0/136] in tuto abinit tests. Test list: {v4:[01,02,03],wannier90:[00,01,02]}.
Variable type: integer
Default is 1 if tfkinfunc==1,
1 if usepaw==1,
0 otherwise.
When this flag is activated, the non-local operator is applied using an algorithm based on spherical harmonics. Non-local projectors are used with their usual form:
P
lmn
(r)=Y
lm
(r)*p
ln
(r)
When useylm=0, the sum over Y_lm can be reduced to a Legendre polynomial form.
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wfoptalg
Mnemonics: WaveFunction OPTimisation ALGorithm
Executable: abinit
Characteristic: DEVELOP
Mentioned in topic: SCFAlgorithms.
Rarely used: [9/907] in abinit tests, [0/136] in tuto abinit tests. Test list: {gpu:[01,03,05],paral:[30,41],v3:[45],v4:[93,94],v5:[75]}.
Variable type: integer
Default is AUTO_FROM_PSP (Comment: 0 when usepaw=0 (norm-conserving pseudopotentials), 10 when usepaw=1 (PAW) ; 114 if paral_kgb=1.)
Allows one to choose the algorithm for the optimisation of the wavefunctions.
The different possibilities are :
-
wfoptalg=0 : standard state-by-state conjugate gradient algorithm,
with no possibility to parallelize over the states;
-
wfoptalg=2 : minimisation of the residual with respect
to different shifts, in order to cover the whole set of occupied
bands, with possibility to parallelize over blocks of states (or bands).
The number of states in a block
is defined in nbdblock.
THIS IS STILL IN DEVELOPMENT.
-
wfoptalg=3 : minimisation of the residual with respect
to a shift. Available only in the non-self-consistent case
iscf=-2,
in order to find eigenvalues and wavefunctions close to a
prescribed value.
-
wfoptalg=4 : (see also wfoptalg=14), a parallel code based on the Locally Optimal
Block Preconditioned Conjugate Gradient (LOBPCG) method of Knyazev.
Reference : A.V. Knyazev, "Toward the Optimal Preconditioned Eigensolver
: Locally Optimal Block Preconditioned Conjugate Gradient Method". SIAM
Journal on Scientific Computing 23, pp517-541 (2001)
.
The implementation rests on the
matlab program by Knyazev
.
Reference A. V. Knyazev, I. Lashuk, M. E. Argentati, and E. Ovchinnikov,
Block Locally Optimal Preconditioned Eigenvalue Xolvers (BLOPEX) in
hypre and PETSc (2007). SIAM Journal on Scientific Computing (SISC).
25(5): 2224-2239
.
For more information see
F. Bottin, S. Leroux, A. Knyazev, G. Zerah, Large scale
ab initio calculations based on three levels of parallelization. (2008).
Computational Material Science, 42(2), 329-336.
-
wfoptalg=10 : (for PAW) standard state-by-state conjugate gradient algorithm,
with no possibility to parallelize over the states, but modified
scheme described in Kresse, Furthmuller, PRB 54, 11169 (1996)
(modified kinetic energy, modified preconditionning, minimal
orthogonalization, ...) ;
-
wfoptalg=14 :
the recommended for parallel code, the same as wfoptalg=4 except that the preconditioning of
the block vectors does not depend on the kinetic energy of each band,
and the orthogonalization after the LOBPCG algorithm is no longer
performed. The first modification increases the convergence and the
second one the efficiency.
-
wfoptalg=114 :
A new version of wfoptalg=14 which is more efficient for few blocks and can take advantage of OpenMP if abinit is compiled with a multithreaded linear algebra library.
With more than 1 thread npfft shoud NOT be used for the time being.
-
wfoptalg=1 :
new algorithm based on Chebyshev filtering, designed for very large number of processors, in the regime where LOBPCG does not scale anymore. It is not able to use preconditionning and therefore might converge slower than other algorithms. By design, it will
not
converge the last bands: it is recommended to use slightly more bands than necessary. For usage with tolwfr, it is imperative to use nbdbuf. For more performance, try use_gemm_nonlop. For more information, see the
performance guide
and the
paper
by A. Levitt and M. Torrent. Status: experimental but usable. Questions and bug reports should be sent to antoine (dot) levitt (at) gmail.com.
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xc_denpos
Mnemonics: eXchange-Correlation - DENsity POSitivity value
Executable: abinit
Characteristic: DEVELOP
Mentioned in topic: xc.
Rarely used: [1/907] in abinit tests, [0/136] in tuto abinit tests. Test list: {libxc:[13]}.
Variable type: real
Default is 1e-14
For the evaluation of the exchange-correlation functionals, the density
cannot be negative, or even too small (e.g. the LDA exchange kernel
behaves like the density at power -(2/3), and the density is used at the denominator
of different factors in GGAs and metaGGAs.
xc_denpos is the smallest value that the density can assume at the time of the
evaluation of a XC functional, in ABINIT. When then computed density drops below xc_denpos
before attacking the evaluation of the XC functional, then it will be (only for that purpose)
replaced by xc_denpos. Note that the evaluation of the gradients or other quantities
that are density-dependent is performed before this replacement.
It has been observed that the SCF cycle of the Tran-Blaha mGGA can be quite hard to make converge, for systems
for which there is some vacuum. In this case, setting xc_denpos to 1.0e-7 ... 1.0e-6 has been seen
to allow good convergence. Of course, this will affect the numerical results somehow, and one should play
a bit with this value to avoid incorrect calculations.
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xc_tb09_c
Mnemonics: Value of the c parameter in the eXchange-Correlation TB09 functional
Executable: abinit
Mentioned in topic: xc.
Rarely used: [1/907] in abinit tests, [0/136] in tuto abinit tests. Test list: {libxc:[13]}.
Variable type: real
Default is 99.99
The modified Becke-Johnson exchange-correlation functional by Tran and Blaha (Phys. Rev. Lett. 102, 226401 (2009)) reads :
V_x(r) = c * V_x^{BR}(r) + (3*c - 2) * 1/pi * sqrt(5/12) * sqrt(2*kden(r)/den(r))
in which V_x^{BR}(r) is the Becke-Roussel potential.
In this equation the parameter c can be evaluated at each SCF step according to the following equation :
c = alpha + beta * sqrt(1/V_{cell} * \int_{V_{cell}} |grad(den(r))|/den(r) d3r)
The c parameter is evaluated thanks to the previous equation when xc_tb09_c is equal to the "magic" default value 99.99.
The c parameter can also be fixed to some (property-optimized or material-optimized) value by using this variable.
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