Help file for the Anaddb utility of the ABINIT package.
This file explains the use and i/o parameters needed for
the "Analysis of Derivative DataBase" code of the ABINIT package.
This code is able to compute interatomic force constants,
but also, more generally, many different physical properties
from databases containing derivatives of the total energy
(Derivative DataBases  DDB).
The user is not supposed to know how the Derivative
DataBase (DBB) has been generated. He/she should simply know what
material is described by the DDB he/she wants to use.
If he/she is interested in the generation of DDB, and wants to
know more about this
topic, he/she will read different help files of the ABINIT package,
related to the
main code, to the
responsefunction features of the main code,
to the merging code.
It will be easier to discover the
present file with the help of the tutorial, especially
the second lesson on response functions.
It is worthwhile to print this help file, for ease of reading.
Copyright (C) 19982013 ABINIT group (XG,DCA)
This file is distributed under the terms of the GNU General Public
License, see
~abinit/COPYING or
http://www.gnu.org/copyleft/gpl.txt .
For the initials of contributors, see
~abinit/doc/developers/contributors.txt .
Content of the help file.
1. Introduction
In short, a Derivative DataBase contains a list of derivatives
of the total energy with respect to three kind of perturbations :
phonons, electric field and stresses. The present code analyses
the DDB, and directly gives properties of the material under
investigation, like phonon spectrum, frequencydependent dielectric
tensor, thermal properties.
Given an input file (parameters described below),
the user must create a "files" file which lists names for the files
the job will require, including the main input file, the main output file,
the name of the DDB, and some other file names optionally used for selected capabilities of the code.
The files file (called for example ab.files) could look like:
anaddb.in
anaddb.out
ddb
band_eps
gkk
anaddb.ep
ddk
In this example:
 the main input file is called "anaddb.in",
 the main output will be put into the file called "anaddb.out",
 the input DDB file is called "ddb",
 information to draw phonon band structures will go to band_eps
 the input GKK file is called "gkk" (used only for electronphonon interactions)
 the base filename for electronphonon output "anaddb.ep" (used only for electronphonon interactions)
 the file name for ddk reference files: these are the GKK files generated in kpoint derivative runs, using the prtgkk abinit input variable (used only for electronphonon transport calculations)
Other examples are given in the ~abinit/test/v2 directory. The latter three filename information
is often not used by anaddb.
The maximal length
of names for the main input or output files is presently 132 characters.
The main executable file is called anaddb.
Supposing that the "files" file is called anaddb.files,
and that the executable is placed in your working directory, anaddb is run
interactively (in Unix) with the command
 anaddb < anaddb.files >& log
or, in the background, with the command
 anaddb < anaddb.files >& log &
where standard out and standard error are piped
to the log file called "log"
(piping the standard error, thanks to the '&' sign placed after '>'
is really important
for the analysis of eventual failures, when not due
to ABINIT, but to other sources, like disk full problem ...).
The user can specify
any names he/she wishes for any of these files.
Variations of the above commands
could be needed,
depending on the flavor of UNIX that is used on the platform
that is considered for running the code.
The syntax of the input file is strictly similar to the syntax of
the
main abinit input files : the file is parsed, keywords are identified,
comments are also identified. However, the multidataset mode is not
available.
We now list the input variables for the anaddb input file. In order
to discover them, it is easier to use the different lessons of the tutorial :
start with the second lesson on response functions,
then follow the lesson on elasticity and piezoelectricity,
the lesson on electronphonon interaction, and
the lesson on nonlinear properties.
If you are discovering this file with the help of the tutorial,
you can go back to the tutorial window.
2. The list of input variables.
Alphabetical list of input variables for ANADDB.
A.
alphon
asr
atftol
atifc
a2fsmear
B.
brav
C.
chneut
D.
dieflag
dipdip
dosdeltae
dossmear
dostol
dossum
E.
eivec
elaflag
elphflag
elphsmear
elph_fermie
enunit
ep_keepbands
ep_int_gkk
ep_b_max
ep_b_min
ep_extrael
ep_nqpt
ep_prt_yambo
ep_qptlist
ep_scalprod
F.
freeze_displ
frmax
frmin
G.
gkqwrite
H.
I.
iatfix
iatprj_bs
iavfrq
ifcana
ifcflag
ifltransport
ifcout
instrflag
istrfix
J.
K.
kptrlatt
kptrlatt_fine
L.
M.
mustar
N.
natfix
natifc
natprj_bs
nchan
nfreq
ngqpt
ng2qpt
ngrids
nlflag
nph1l
nph2l
nqpath
nqshft
nsphere
nstrfix
ntemper
nwchan
O.
outscphon
outboltztrap
P.
piezoflag
polflag
prtfsurf
prtsrlr
prtmbm
prtdos
prtnest
Q.
qgrid_type
qpath
qph1l
qph2l
qrefine
q1shft
q2shft
R.
ramansr
relaxat
relaxstr
rfmeth
rifcsph
S.
selectz
symdynmat
symgkq
T.
targetpol
telphint
temperinc
tempermin
thmflag
thmtol
U.
use_k_fine
V.
W.
X.
Y.
Z.
alphon
Mnemonics: ALign PHONon mode eigendisplacements
Characteristic:
Variable type: integer
Default: 0
In case alphon is set to 1, ANADDB will compute linear combinations of
the eigendisplacements of modes that are degenerate (twice or three times),
in order to align the mode effective charges along the cartesian axes.
This option is useful in the modebymode decomposition of the
electrooptic tensor, and to compute
the Raman susceptibilities of individual phonon modes.
In case of uniaxial crystals, the zaxis should be chosen along the optical axis.
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 List of ANADDB input variables
asr
Mnemonics: Acoustic Sum Rule
Characteristic:
Variable type: integer
Default: 1 (was 0 before v5.3)
Govern the imposition of the Acoustic Sum Rule (ASR).
 0 => no ASR for interatomic force constants is imposed.
 1 or 2 => the ASR for interatomic force constants
is imposed by modifying the onsite interatomic force constants,
in a symmetric way (asr=2), or in the more general case,
unconstrained way (asr=1).
More detailed explanations : the total energy should be
invariant under translation of the crystal as a whole. This
would garantee that the three lowest phonon modes at Gamma
have zero frequency (Acoustic Sum Rule  ASR).
Unfortunately, the way the DDB is
generated (presence of a discrete grid of points for the
evaluation of the exchangecorrelation potential and energy)
slightly breaks the translational invariance.
Well, in some pathological cases, the breaking can be rather
important.
Two quantities are affected : the interatomic forces
(or
dynamical matrices), and the effective charges.
The ASR for the effective charges is called the charge
neutrality sum rule, and will be dealt with by the variable
chneut.
The ASR for the interatomic forces can be restored,
by modifying the interatomic force of the atom on itself,
(called selfIFC), as soon as the dynamical matrix at Gamma
is known. This quantity
should be equal to minus the sum of all interatomic
forces generated by all others atoms (actionreaction law!),
which is determined by the dynamical matrix at Gamma.
So, if asr is nonzero, the correction to the selfforce
will be determined, and the selfforce will be imposed
to be consistent with the ASR.
This correction will work if IFCs are computed
(ifcflag/=0),
as well as if the IFCs are not computed
(ifcflag==0).
In both cases, the phonon frequencies will not be the same
as the ones determined by the output of abinit, RF case.
If you want to check that the DDB is correct, by comparing
phonon frequencies from abinit and anaddb, you should turn off
both asr and
chneut.
Until now, we have not explained the difference
between
asr=1 and asr=2. This is rather subtle.
In some local lowsymmetry
cases (basically the effective charges should be anisotropic),
when the dipoledipole contribution is evaluated and subtracted,
the ASR cannot be imposed without breaking the
symmetry of the onsite interatomic forces. That explains why two
options are given : the second case (asr=2, sym) does not
entirely impose the ASR, but simply the part that keeps the onsite
interatomic forces symmetric (which means that the acoustic frequencies
do not go to zero exactly), the first case (asr=1, asym)
imposes the ASR, but breaks the symmetry.
asr=2 is to be preferred for the analysis of the interatomic
force
constant in real space, while asr=1 should be used to get
the phonon band structure.
(NOTE : in order to confuse even more the situation,
it seems that the acoustic phonon frequencies generated by the code
for both the sym and asym options are exactly the same ...
likely due to an extra symmetrisation in the diagonalisation routine.
Of course, when
the matrix at Gamma has been generated from IFCs coming from dynamical
matrices none of which are Gamma, the breaking of the ASR is rather
severe. In order to clear the situation, one should use
a diagonalisation
routine for nonhermitian matrices. So, at the present status of
understanding, one should always use the asr=2 option ).
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 List of ANADDB input
variables
atftol
Mnemonics: ATomic Temperature Factor TOLerance
Characteristic:
Variable type: real
Default: 0.05
The relative tolerance on the atomic temperature
factors.
This number will determine when the series of channel widths
with which the DOS is calculated can be stopped, i.e.
the mean of the relative change going from one grid
to the next bigger is smaller than wtol2.
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 List of ANADDB input
variables
atifc
Mnemonics: AToms for IFC analysis
Characteristic:
Variable type: integer array atifc(
natifc)
Default: 0
The actual numbers of the atoms for which the
interatomic
force constant have to be written and eventually analysed.
WARNING : there will be an inplace change of meaning of atifc (this is
confusing,
and should be taken away in one future version  sorry for this).
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 List of ANADDB input
variables
a2fsmear
Mnemonics: Alpha2F SMEARing factor
Characteristic: ENERGY
Variable type: real
Default: 0.00002
Smearing width for the Eliashberg alpha^2F function
(similar to
a phonon DOS), which is sampled on a finite q and k grid. The Dirac
delta
functions in energy are replaced by Gaussians of width a2fsmear
(by default in Hartree).
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 List of ANADDB input
variables
brav
Mnemonics: BRAVais
Characteristic:
Variable type: integer
Default: 1
Allows to specify the Bravais lattice of the crystal,
in order to help to generate a grid of special q points.
 1 => all the lattices (including FCC, BCC
and hexagonal)
 2 => specific for Face Centered lattices
 3 => specific for Body Centered lattices
 4 => specific for the Hexagonal lattice
Note that in the latter case, the rprim of
the unit cell have to be 1.0 0.0 0.0 .5 sqrt(3)/2 0.0 0.0 0.0 1.0
in order for the code to work properly.
Warning : the generation of qpoints in anaddb is rather
oldfashioned, and should be replaced by routines used by
the main abinit code.
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 List of ANADDB input variables
chneut
Mnemonics: Integer for CHarge NEUTrality treatment
Characteristic:
Variable type: integer parameter
Default is 0.
Set the treatment of the Charge Neutrality requirement for
the effective charges.
 chneut=0 => no ASR for effective charges is imposed
 chneut=1 => the ASR for effective charges is imposed
by giving to each atom an equal portion
of the missing charge. See Eq.(48) in Phys. Rev. B55, 10355 (1997).
 chneut=2 => the ASR for effective charges is imposed
by giving to each atom a portion of the
missing charge proportional to the screening charge
already present. See Eq.(49) in Phys. Rev. B55, 10355 (1997).
More detailed explanation : the sum of the effective charges
in the unit cell should be equal to zero. It is not the case
in the DDB, and this sum rule is sometimes strongly violated.
In particular, this will make the lowest frequencies at Gamma
nonzero. There is no "best" way of imposing the ASR
on effective charges.
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 List of ANADDB input variables
dieflag
Mnemonics: DIElectric FLAG
Characteristic:
Variable type: integer
Default: 0
Integer. Frequencydependent dielectric tensor flag.
 0 => No dielectric tensor is calculated.
 1 => The frequencydependent dielectric tensor is calculated.
The frequencies are defined by the
nfreq,
frmin,
frmax
variables. Also, the generalized LyddaneSachsTeller
relation will be used as an independent check of the
dielectric tensor at zero frequency (this for the
directions defined in the phonon list 2.
See nph2l).
 2 => Only the electronic dielectric tensor is calculated.
It corresponds to a zerofrequency homogeneous field,
with quenched atomic positions. For large band gap materials,
this quantity is measurable because the highest phonon
frequency is on the order of a few tenths of eV, and the
band gap is larger than 5eV.
 3 => Compute and print the relaxedion dielectric tensor.
Requirements for preceding responsefunction DDB generation
run: electricfield and full atomicdisplacement responses.
Set rfstrs = 1, 2, or 3 (preferably 3).
Set rfatpol and
rfdir to do a full calculation of
phonons at Q=0 (needed because the inverse of
forceconstant tensor is required).
Note that the relaxedion dielectric tensor computed here can
also be obtained as the zerofrequency limit of the
frequencydependent dielectric tensor using input variables
dieflag=1 and frmin=0.0. (The results obtained using these two
approaches should agree to good numerical precision.) The ability
to compute and print the static dielectric tensor here is provided
for completeness and consistency with the other tensor
quantities that are computed in this section of the code.
 4 => Calculate dielectric tensor of both relaxed ion and
free stress.
We need information of internal strain and elastic tensor (relaxed ion)
in this computation. So please set:
elaflag=2,3,4 or 5 and
instrflag=1
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 List of ANADDB input variables
dipdip
Mnemonics: DIPoleDIPole interaction
Characteristic:
Variable type: integer
Default: 1

0 => the dipoledipole interaction is not handled separately
in the treatment of the interatomic forces. This option
is available for testing purposes or if effective charge
and/or dielectric tensor is not available in the derivative
database. It gives results much less accurate than dipdip=1.

1 => the dipoledipole interaction is subtracted from the dynamical
matrices before Fourier transform, so that only the shortrange
part is handled in real space. Of course, it is reintroduced
analytically when the phonon spectrum is interpolated, or if
the interatomic force constants have to be analysed in real space.
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 List of ANADDB input variables
dosdeltae
Mnemonics: DOS DELTA in Energy
Characteristic:
Variable type: real
Default: 4.5E06 Hartree = 1 cm^{1}
The input variable dosdeltae is used to define the step of the frequency grid used to
calculate the phonon density of states when prtdos=1.
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 List of ANADDB input variables
dossmear
Mnemonics: DOS SMEARing value
Characteristic: Energy
Variable type: real
Default: 4.5E05 Hartree = 10 cm^{1}
dossmear defines the gaussian broadening used to calculate the phonon density
of states when prtdos=1.
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 List of ANADDB input variables
dostol
Mnemonics: DOS TOLerance
Characteristic:
Variable type: real
Default: 0.25
The relative tolerance on the phonon density of state.
This number will determine when the series of grids
with which the DOS is calculated can be stopped, i.e.
the mean of the relative change going from one grid
to the next bigger is smaller than dostol.
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 List of ANADDB input variables
dossum
Mnemonics: DOS SUM
Characteristic:
Variable type: integer
Default: 0
Set the flag to calculate the two phonon dos density of states. Sum and Difference for
the Gamma point. The DOS is converged and based on that, the sum and different is
reported in the output file dossum.
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 List of ANADDB input variables
eivec
Mnemonics: EIgenVECtors
Characteristic:
Variable type: integer
Default: 0
 0 => do not write the phonon eigenvectors;
 1 or 2 => write the phonon eigenvectors;
 3 => write the phonon eigenvectors, in the lwfformatted file;
 4 => generate output files for band2eps (drawing tool for the phonon band structure);
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 List of ANADDB input variables
elaflag
Mnemonics: ELAstic tensor FLAG
Characteristic:
Variable type: integer
Default: 0
Flag for calculation of elastic and compliance tensors
 0 => No elastic or compliance tensor will be calculated.
 1 => Only clampedion elastic and compliance tensors will be
calculated.
Requirements for preceding responsefunction DDB generation
run: Strain perturbation.
Set rfstrs to 1, 2, or 3.
Note that rfstrs=3 is recommended so that responses to
both uniaxial and shear strains will be computed.
 2 => Both relaxed and clampedion elastic and compliance tensor
will be calculated, but only the relaxedion quantities
will be printed.
The input variable instrflag
should also be set to 1, because
the internalstrain tensor is needed to compute the relaxedion
corrections. Requirements for preceding responsefunction DDB
generation run: Strain and atomicdisplacement responses at Q=0.
Set rfstrs = 1, 2, or 3 (preferably 3).
Set rfatpol and
rfdir to do a full calculation of
phonons at Q=0 (needed because the inverse of
forceconstant tensor is required).
 3 => Both relaxed and clampedion elastic and compliance tensors
will be printed out.
The input variable instrflag
should also be set to 1.
Requirements for preceeding responsefunction DDB generation
run: Same as for elaflag=2.
 4 => Calculate the elastic and compliance tensors (relaxed ion)
at fixed displacement field, the relaxedion tensors at fixed
electric field will be printed out too, for comparison.
When elaflag=4, we need the information of internal strain and
relaxedion dielectric tensor to build the whole tensor, so
we need set instrflag=1 and
dieflag=3 or 4 .
 5 => Calculate the relaxed ion elastic and compliance tensors, considering
the stress left inside cell. At the same time, bare relaxed ion tensors
will still be printed out for comparison.
In this calculation, stress tensor is needed to compute the correction
term, so one supposed to merge the first order derivative data base (DDB file)
with the second order derivative data base (DDB file) into a new DDB file, which
can contain both information. And the program will also check for the users.
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 List of ANADDB input variables
elphflag
Mnemonics: ELectronPHonon FLAG
Characteristic:
Variable type: integer
Default: 0
If elphflag is 1, anaddb performs an analysis of the electronphonon coupling.
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 List of ANADDB input variables
elphsmear
Mnemonics: ELectronPHonon SMEARing factor
Characteristic: ENERGY
Variable type: real
Default: 0.01 Hartree
Smearing width for the Fermi surface integration (in Hartree by default).
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 List of ANADDB input variables
elph_fermie
Mnemonics: ELectronPHonon FERMI Energy
Characteristic: ENERGY
Variable type: real
Default: 0.0
If nonzero, will fix artificially the value of the Fermi energy
(e.g. for semiconductors), in the electronphonon case. Note that elph_fermie and ep_extrael
should not be used at the same time.
(elphflag=1).
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 List of ANADDB input variables
enunit
Mnemonics: ENergy UNITs
Characteristic:
Variable type: integer
Default: 0
Give the energy for the phonon frequency output
(in the output file, not in the console log file, for
which Hartree units are used).
 0 => Hartree and cm1;
 1 => meV and Thz;
 2 => Hartree, cm1, meV, Thz, and Kelvin.
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 List of ANADDB input variables
ep_b_max
Mnemonics: Electron Phonon integration Band MAXimum
Characteristic:
Variable type: integer
Default: 0
When set, and telphint is equal to 2, this variable determines the kpoint integration weights which are used in the electronphonon part of the code. Instead of weighting according to a distance from the Fermi surface, an equal weight is given to all kpoints, for all bands between ep_b_min and ep_b_max.
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 List of ANADDB input variables
ep_b_min
Mnemonics: Electron Phonon integration Band MINimum
Characteristic:
Variable type: integer
Default: 0
As for ep_b_max, but ep_b_min is the lower bound on the band integration, instead of the upper bound. See also telphint
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 List of ANADDB input variables
ep_extrael
Mnemonics: ElectronPhonon EXTRA ELectrons
Characteristic:
Variable type: real
Default: 0.0
If nonzero, will fix artificially the number of extra electrons per unit cell, according to a doped case.
(e.g. for semiconductors), in the electronphonon case. Note that ep_extrael and elph_fermie should not be used at the same time.
(elphflag=1).
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 List of ANADDB input variables
ep_int_gkk
Mnemonics: ElectronPhonon INTerpolation of GKK
Characteristic:
Variable type: integer
Default: 0
This flag determines whether the interpolation of the electronphonon matrix
elements over the coarse kgrid is done (ep_int_gkk 1) before summing
with appropriate Fermi Surface weights. In this way, the two integration weights
are treated symmetrically.
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 List of ANADDB input variables
ep_keepbands
Mnemonics: ElectronPhonon KEEP dependence on electron BANDS
Characteristic:
Variable type: integer
Default: 0
This flag determines whether the dependency of the electronphonon matrix
elements on the electron band index is kept (ep_keepbands 1), or whether
it is summed over immediately with appropriate Fermi Surface weights. For
transport calculations ep_keepbands must be set to 1.
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 List of ANADDB input variables
ep_nqpt
Mnemonics: Electron Phonon Number of Q PoinTs
Characteristic:
Variable type: integer
Default: 0
In case a nonuniform grid of qpoints is being used, for direct calculation
of the electronphonon quantities without interpolation, this specifies the
number of qpoints to be found in the GKK file, independently of the normal
anaddb input (ngqpt)
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 List of ANADDB input variables
ep_prt_yambo
Mnemonics: Electron Phonon PRinTout YAMBO data
Characteristic:
Variable type: integer
Default: 0
For electronphonon calculations, print out matrix elements for use by the yambo code.
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 List of ANADDB input variables
ep_qptlist
Mnemonics: Electron Phonon Q PoinT LIST
Characteristic:
Variable type: real array of 3*ep_nqpt elements
Default: *0
In case a nonuniform grid of qpoints is being used, for direct calculation
of the electronphonon quantities without interpolation, this specifies the
qpoints to be found in the GKK file, independently of the normal
anaddb input (ngqpt), in reduced coordinates of the reciprocal space lattice.
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 List of ANADDB input variables
ep_scalprod
Mnemonics: DO SCALar PRODuct for gkk matrix elements
Characteristic:
Variable type: integer
Default: 0
The input variable ep_scalprod is a flag determining whether the scalar
product of the electronphonon matrix elements (gkk) with the phonon
displacement vectors is done before or after interpolation. Doing so before
(ep_scalprod 1) makes phonon linewidths smoother but introduces an error,
as the interpolated phonons and gkk are not diagonalized in the same basis.
Doing so afterwards (ep_scalprod 0) eliminates the diagonalization error,
but sometimes gives small spikes in the phonon linewidths near band crossings
or high symmetry points. I do not know why...
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 List of ANADDB input variables
freeze_displ
Mnemonics: FREEZE DISPLacement of phonons into supercells
Characteristic:
Variable type: real number
Default: 0.0
If different from zero, freeze_displ will be used as the amplitude of a phonon displacement.
For each qpoint and mode in the qph1l list,
a file will be created containing a supercell
of atoms with the corresponding phonon displacements frozen in.
This is typically useful to freeze a soft phonon mode, then let it relax in abinit
afterwards.
freeze_displ is unitless, but has a physical meaning: it is related to the Bose
distribution n_B and the frequency w_qs of the phonon mode. At a given temperature T,
freeze_displ will give the mean square displacement of atoms (along with the displacement
vectors, which are in Bohr). In atomic units freeze_displ = sqrt((0.5 + n_B(w_qs/kT) / w_qs)
Typical values are 50200 for a frequency of a few hundred cm1 and room temperature. If all you want
is to break the symmetry in the right direction, any reasonable value (1050) should be ok.
WARNING: this will create a lot of files (3*natom*nph1l), so it should be used with a small number
nph1l of qpoints for interpolation.
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 List of ANADDB input variables
frmax
Mnemonics: FRequency : MAXimum
Characteristic:
Variable type: real number
Default: 10.0
Value of the largest frequency for the
frequencydependent dielectric tensor, in Hartree.
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 List of ANADDB input variables
frmin
Mnemonics: FRequency : MINimum
Characteristic:
Variable type: real number
Default: 0.0
Value of the lowest frequency for the
frequencydependent dielectric tensor, in Hartree.
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 List of ANADDB input variables
gkqwrite
Mnemonics: GKk for input Q grid to be WRITtEn to disk
Characteristic:
Variable type: integer
Default: 0
Flag to write out the reciprocal space matrix elements to a disk file named
gkqfile. This reduces strongly the memory needed for an electronphonon run.
iavfrq
Mnemonics: Integer for the printing of AVerage FReQuency
Characteristic:
Variable type: integer
Default: 0
Used only when thmflag=1.
When this flag is set to 1, the "average frequency" is printed out (as a
function of temperature, with phonon internal energy, free energy, entropy, ...).
The average frequency is defined as:
Omega_average = Sum_over_q_and_i [Cv_iq Omega_iq]/Cv
where
 Omega_iq is the frequency of the ith mode for qpoint q
 Cv is the specific heat
 Cv_iq is the contribution to the specific heat of the ith mode for qpoint q
The "average frequency" can be used to have an estimation of the average
Gruneisen parameter: Gamma_average=d(log(Omega_average))/d(log(V)).
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 List of ANADDB input variables
iatfix
Mnemonics: Indices of the AToms that are FIXed
Characteristic:
Variable type: integer array (1:natfix)
Default: 0
Indices of the atoms that are fixed during a structural relaxation at constrained polarization.
See polflag.
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 List of ANADDB input variables
iatprj_bs
Mnemonics: Indices of the AToms for the PRoJection of the phonon Band Structure
Characteristic:
Variable type: integer array (1:natprj_bs)
Default: 0
Indices of the atoms that are chosen for projection of the phonon eigenvectors, giving a weighted phonon band structure file.
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 List of ANADDB input variables
ifcana
Mnemonics: IFC ANAlysis
Characteristic:
Variable type: integer
Default: 0
 0 => no analysis of interatomic force constants;
 1 => analysis of interatomic force constants.
If the analysis is activated, one get the
trace of the matrices between pairs of atoms,
if dipdip is 1,
get also the trace of the shortrange
and electrostatic part, and
calculate the ratio with the full matrice;
then define a local coordinate reference (using
the nextneighbour coordinates), and express
the interatomic force constant matrix between
pairs of atoms in that local coordinate reference
(the first vector is along the bond; the second
vector is along the perpendicular force exerted
on the generic atom by a longitudinal displacement
of the neighbouring atom  in case it does not vanish;
the third vector is perpendicular to the two other)
also calculate ratios with respect to the
longitudinal force constant ( the (1,1) element of
the matrix in local coordinates).
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 List of ANADDB input variables
ifcflag
Mnemonics: Interatomic Force Constants FLAG
Characteristic:
Variable type: integer
Default: 0
 0 => do all calculations directly from the DDB, without the
use of the interatomic force constant.
 1 => calculate and use the interatomic force constants
for interpolating the phonon spectrum and dynamical
matrices at every q wavevector, and eventually analyse
the interatomic force constants, according to the
informations given by
atifc,
dipdip,
ifcana,
ifcout,
natifc,
nsphere,
rifcsph.
More detailed explanations : if the dynamical matrices
are known on a regular set of wavevectors, they
can be used to get the interatomic forces, which are simply
their Fourier transform. When nonanalyticities
can been removed by the use of effective charge at Gamma
(option offered by putting
dipdip to 1),
the interatomic forces are known to decay rather fast (in real space).
The interatomic forces generated from a small set of
dynamical matrices
could be of sufficient range to allow
the remaining interatomic forces to be neglected.
This gives a practical way to interpolate the content
of a small set of dynamical matrices, because dynamical
matrices can everywhere be generated starting from this
set of interatomic force constants. It is suggested to
always use ifcflag=1. The ifcflag=0 option
is available for
checking purpose, and if there is not enough information
in the DDB.
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 List of ANADDB input variables
ifcout
Mnemonics: IFC OUTput
Characteristic:
Variable type: integer
Default: 0
For each atom in the list
atifc (generic atoms),
ifcout give the number
of neighbouring atoms for which the ifc's will be
output (written) and eventually analysed. The
neighbouring atoms are selected by decreasing distance with respect to
the generic atom.
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 List of ANADDB input variables
ifltransport
Mnemonics: IFLag for TRANSPORT
Characteristic:
Variable type: integer
Default: 0
if ifltransport=1 (LOVA) or ifltransport=2 (nonLOVA), anaddb calculates the transport
properties: electrical and thermal resistivities from electronphonon
interactions (needs elphflag = 1)
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 List of ANADDB input variables
instrflag
Mnemonics: INternal STRain FLAG
Characteristic:
Variable type: integer
Default: 0
Internal strain tensor flag.
 0 => No internalstrain calculation.
 1 => Print out both forceresponse and displacementresponse
internalstrain tensor.
Requirements for preceding responsefunction DDB generation
run: Strain and full atomicdisplacement responses.
Set rfstrs = 1, 2, or 3 (preferably 3).
Set rfatpol and
rfdir to do a full calculation of
phonons at Q=0.
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 List of ANADDB input variables
istrfix
Mnemonics: Index of STRain FIXed
Characteristic:
Variable type: integer array istrfix(1:nstrfix)
Default: 0
Indices of the elements of the strain tensor that are fixed during a structural relaxation
at constrained polarisation :
 0 => No elastic or compliance tensor will be calculated.
 1 => Only clampedion elastic and compliance tensors will be
calculated. Requirements for preceding responsefunction DDB generation
run: Strain perturbation. Set rfstrs to 1, 2, or 3.
Note that rfstrs=3
is recommended so that responses to both uniaxial and shear strains
will be computed.
 2 => Both relaxed and clampedion elastic and compliance
tensor will be calculated, but only the relaxedion quantities will be
printed. The input variable instrflag
should also be set to 1, because the internalstrain tensor is needed
to compute the relaxedion corrections. Requirements for preceding
responsefunction DDB generation run: Strain and atomicdisplacement
responses at Q=0. Set rfstrs
= 1, 2, or 3 (preferably 3). Set rfatpolrfatpol and rfdir to do a full
calculation of phonons at Q=0 (needed because the inverse of
forceconstant tensor is required).
 3 => Both relaxed and clampedion elastic and compliance
tensors will be printed out. The input variable instrflag should also be set to
1. Requirements for preceeding responsefunction DDB generation run:
Same as for elaflag=2'.
 4 => Calculate the elastic and compliance tensors (relaxed
ion) at fixed displacement field, the relaxedion tensors at fixed
electric field will be printed out too, for comparison. When elaflag=4,
we need the information of internal strain and relaxedion dielectric
tensor to build the whole tensor, so we need set instrflag=1 and dieflag=3 or 4 .
 5 => Calculate the relaxed ion elastic and compliance tensors,
considering the stress left inside cell. At the same time, bare relaxed
ion tensors will still be printed out for comparison. In this
calculation, stress tensor is needed to compute the correction term, so
one supposed to merge the first order derivative data base (DDB file)
with the second order derivative data base (DDB file) into a new DDB
file, which can contain both information. And the program will also
check for the users.
See polflag.
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 List of ANADDB input
variables
kptrlatt
Mnemonics: K PoinT Reciprocal LATTice
Characteristic:
Variable type: integer
Default: 9*0
Un normalized lattice vectors for the kpoint grid in reciprocal space
(see abinit variable definitionas well).
Input needed in electronphonon calculations
using nesting functions or tetrahedron integration.
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 List of ANADDB input
variables
kptrlatt_fine
Mnemonics: K PoinT Reciprocal LATTice for FINE grid
Characteristic:
Variable type: integer
Default: 9*0
As kptrlatt above, but for a finer grid of kpoints. Under development. Does not
work yet, as of June 2010.
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 List of ANADDB input
variables
mustar
Mnemonics: MU STAR
Characteristic:
Variable type: real
Default: 0.1
Average electronelectron interaction strength, for the
computation of the
superconducting Tc using McMillan's formula.
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 List of ANADDB input
variables
natfix
Mnemonics: Number of AToms FIXed
Characteristic:
Variable type: integer
Default: 0
Number of atoms that are fixed during a structural
optimisation at constrained polarization.
See polflag.
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 List of ANADDB input variables
natifc
Mnemonics: Number of AToms for IFC analysis
Characteristic:
Variable type: integer
Default: 0
Give the number of atoms for which ifc's are written
and
eventually analysed. The list of these atoms is provided
by atifc
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 List of ANADDB input variables
natprj_bs
Mnemonics: Number of AToms for PRoJection of the Band Structure
Characteristic:
Variable type: integer
Default: 0
Give the number of atoms for which atomicprojected phonon
band structures will be output. The list of these atoms is provided
by iatprj_bs
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 List of ANADDB input variables
nchan
Mnemonics: Number of CHANnels
Characteristic:
Variable type: integer
Default: 800
The number of channels of width 1 cm1
used in calculating the
phonon density of states through the histogram method,
or, equivalently, the largest frequency sampled.
The first channel begins at 0.
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 List of ANADDB input variables
nfreq
Mnemonics: Number of FREQuencies
Characteristic:
Variable type: integer
Default: 1
Number of frequencies wanted for the
frequencydependent dielectric tensor. Should be positive.
See dieflag.
The code will take nfreq equidistant values from
frmin to
frmax.
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 List of ANADDB input variables
ngqpt
Mnemonics: Number of Grids points for Q PoinTs
Characteristic:
Variable type: integer array ngqpt(3)
Default: 3*0 (will not work)
The MonkhorstPack grid linear dimensions, for the DDB (coarse grid).
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 List of ANADDB input variables
ng2qpt
Mnemonics: Number of Grids points for Q PoinTs (grid 2)
Characteristic:
Variable type: integer array ng2qpt(3)
Default: 3*0 (will not work)
The MonkhorstPack grid linear dimensions, for the finer of the
series of fine grids. Used for the integration
of thermodynamical functions (BoseEinstein distribution)
or for the DOS.
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 List of ANADDB input
variables
ngrids
Mnemonics: Number of GRIDS
Characteristic:
Variable type: integer
Default: 4
This number define the series of grids that will be
used
for the estimation of the phonon DOS. The coarsest will be
tried first, then the next, ... then the one
described by
ng2qpt.
The intermediate grids are defined
for igrid=1... ngrids,
by the numbers ngqpt_igrid(ii)=(ng2qpt(ii)*igrid)/ngrids
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 List of ANADDB input variables
nlflag
Mnemonics: NonLinear FLAG
Characteristic:
Variable type: integer
Default: 0
Nonlinear properties flag.
 0 => do not compute nonlinear properties ;
 1 => the electrooptic tensor, Raman susceptibilities and nonlinear optical
susceptibilities are calculated;
 2 => only the nonlinear optical susceptibilities and firstorder
changes of the dielectric tensor induced by an atomic displacement are calculated;
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 List of ANADDB input variables
nph1l
Mnemonics: Number of PHonons in List 1
Characteristic:
Variable type: integer
Default: 0
The number of wavevectors in phonon list 1, used for interpolation of the phonon frequencies. The
values of these wavevectors will be specified by
qph1l
The dynamical matrix for these wavevectors, obtained
either directly from the DDB  if
ifcflag=0  or through
the interatomic forces interpolation  if
ifcflag=1 ),
will be diagonalized, and the corresponding eigenfrequencies
will be printed.
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 List of ANADDB input variables
nph2l
Mnemonics: Number of PHonons in List 2
Characteristic:
Variable type: integer
Default: 0
The number of wavevectors in phonon list 2, defining the directions
along which the nonanalytical splitting of phonon frequencies
at Gamma will be calculated. The actual
values of the wavevector directions will be specified
by qph2l.
These are actually all wavectors at Gamma, but obtained
by a limit along a different direction in the Brillouinzone.
It is important to note that nonanalyticities in the
dynamical matrices are present at Gamma, due to the
longrange Coulomb forces. So, going to Gamma along different
directions can give different results.
The wavevectors in list 2 will be used to :
 generate and diagonalize a dynamical matrix, and print the
corresponding eigenvalues.
 calculate the generalized LyddaneSachsTeller relation.
Note that if the three first numbers are zero, then
the code will do a calculation at Gamma without
nonanalyticities.
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 List of ANADDB input variables
nqpath
Mnemonics: Number of Q wavevectors defining a PATH
Characteristic:
Variable type: integer
Default: 0
Number of qpoints in the array qpath
defining the path along which the phonon band structure and phonon linewidths
are interpolated.
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 List of ANADDB input variables
nqshft
Mnemonics: Number of Q SHiFTs
Characteristic:
Variable type: integer
Default: 1
The number of vector shifts of the simple Monkhorst and
Pack grid, needed to generate the coarse grid of q points
(for the series of fine grids, the number of shifts it is always taken to be 1).
Usually, put it to 1.
Use 2 if BCC sampling (Warning : not BCC lattice, BCC *sampling*),
and 4 for FCC sampling (Warning : not FCC lattice, FCC *sampling*).
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 List of ANADDB input
variables
nsphere
Mnemonics: Number of atoms in SPHERe
Characteristic:
Variable type: integer
Default: 0
Number of atoms included in the cutoff sphere for
interatomic force constant, see also the alternative rifcsph.
If nsphere= 0 : maximum extent allowed by the grid .
This number defines the atoms for which the
short range part of the interatomic force constants, after
imposition of the acoustic sum rule, will not be put to zero.
This option is available for testing purposes
(evaluate the range of the interatomic force constants), because
the acoustic sum rule will be violated if some atoms are no more
included in the inverse Fourier Transform.
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 List of ANADDB input
variables
nstrfix
Mnemonics: Number of STRain components FIXed
Characteristic:
Variable type: integer
Default: 0
Number of strain component that are fixed during a
structural optimisation at constrained polarization.
See polflag.
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 List of ANADDB input
variables
ntemper
Mnemonics: Number of TEMPERatures
Characteristic:
Variable type: integer
Default: 10
Number of temperatures at which the thermodynamical
quantities have to be evaluated. Now also used for the output of transport
quantities in electronphonon calculations. The full grid is specified
with the tempermin and
temperinc variables.
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 List of ANADDB input variables
nwchan
Mnemonics: Number of Widths of CHANnels
Characteristic:
Variable type: integer
Default: 10
Integer. The width of the largest channel
used to sample the frequencies.
The code will generate different sets of channels,
with decreasing widths (by step of 1 cm1), from
this channel width to 1, eventually. It considers to
have converged when the convergence criterion based on
dostol and
thmtol have been fulfilled.
outscphon
Mnemonics: OUTput files for Self Consistent PHONons
Characteristic:
Variable type: integer
Default: 0
If set to 1, the phonon frequency and eigenvector files needed for a Self Consistent
phonon run (as in Souvatzis PRL 100 095901) will be output to files appended _PHFRQ and _PHVEC.
The third file needed is appended _PCINFO for Primitive Cell INFOrmation.
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 List of ANADDB input
variables
outboltztrap
Mnemonics: OUTput files for BOLTZTRAP code
Characteristic:
Variable type: integer
Default: 0
If set to 1, the phonon frequencies on the ngqpt grid are output in a format legible by the BoltzTrap code,
which does band interpolation and gets group velocities. The output file will be appended _BTRAP
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 List of ANADDB input
variables
piezoflag
Mnemonics: PIEZOelectric tensor FLAG
Characteristic:
Variable type: integer
Default: 0
Flag for calculation of piezoelectric tensors
 0 => No piezoelectric tensor will be calculated.
 1 => Only the clampedion piezoelectric tensor is computed and
printed. Requirements for preceding responsefunction DDB generation
run: Strain and electricfield responses. For the electricfield part,
one needs results from a prior 'ddk perturbation' run. Note that even
if only a limited number of piezoelectric tensor terms are wanted (as
determined by rfstrs and rfdir in this calculation) it is necessary to
set rfdir = 1 1 1 in the d/dk calculation for most structures. The only
obvious exception to this requirement is cases in which the primitive
lattice vectors are all aligned with the cartesian axes. The code will
omit terms in the output piezoelectric tensor for which the available
d/dk set is incomplete. Thus: Set rfstrs to 1, 2, or 3i
(preferably 3)
 2 => Both relaxed and clampedion elastic and compliance
tensor will be calculated, but only the relaxedion quantities will be
printed. The input variable instrflag
should also be set to 1, because the internalstrain tensor is needed
to compute the relaxedion corrections. Requirements for preceding
responsefunction DDB generation run: Strain, electricfield and full
atomicdisplacement responses at Q=0. Set rfstrs = 1, 2, or 3
(preferably 3). Set rfelfd
= 3. Set rfatpol
and rfdir to do a
full calculation of phonons at Q=0 (needed because the inverse of
forceconstant tensor is required).
 3 => Both relaxed and clampedion piezoelectric tensors will
be printed out. The input variable instrflag
should also be set to 1. Requirements for preceding responsefunction
DDB generation run: Same as for piezoflag=2.
 4 => Calculate the piezoelectric d tensor (relaxed ion). In
order to calculate the piezoelectric d tensor, we need information of
internal strain and elastic tensor (relaxed ion). So we should set elaflag= 2,3,4, or 5 and instrflag=1. The subroutine will
also do a check for you, and print warning message without stopping
even if flags were not correctly set.
 5 => Calculate the piezoelectric g tensor (relaxed ion). In
this computation, we need information of internal strain, elastic
tensor (relaxed ion) and dielectric tensor (relaxed ion). So we should
set: instrflag=1, elaflag=2,3,4 or 5, dieflag=3 or 4. The subroutine
will also do a check for you, and print warning message without
stopping even if flags were not correctly set.
 6 => Calculate the piezoelectric h tensor (relaxed ion). In
this calculation, we need information of internal strain and dielectric
tensor (relaxed ion). So we need set: instrflag=1 and dieflag=3 or 4. The subroutine
will also do a check for you, and print warning message without
stopping even if flags were not correctly set.
 7 => calculate all the possible piezoelectric tensors,
including e (clamped and relaxed ion), d, g and h tensors. The flags
should be set to satisfy the above rules from 1 to 6.
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 List of ANADDB input variables
piezoflag
Mnemonics: PIEZOelectric tensor FLAG
Characteristic:
Variable type: integer
Default: 0
Flag for calculation of piezoelectric tensors
 0 => No piezoelectric tensor will be calculated.
 1 => Only the clampedion piezoelectric tensor is computed and
printed. Requirements for preceding responsefunction DDB generation
run: Strain and electricfield responses. For the
electricfield part, one needs results from a prior 'ddk
perturbation' run. Note that even if only a limited number
of piezoelectric tensor terms are wanted (as determined by
rfstrs and rfdir in this calculation) it is necessary to set
rfdir = 1 1 1 in the d/dk calculation for most structures.
The only obvious exception to this requirement is cases in
which the primitive lattice vectors are all aligned with the
cartesian axes. The code will omit terms in the output
piezoelectric tensor for which the available d/dk set is
incomplete. Thus:
Set rfstrs to 1, 2, or 3i (preferably 3)
 2 => Both relaxed and clampedion elastic and compliance tensor
will be calculated, but only the relaxedion quantities
will be printed.
The input variable instrflag
should also be set to 1, because
the internalstrain tensor is needed to compute the relaxedion
corrections. Requirements for preceding responsefunction DDB
generation run: Strain, electricfield and full atomicdisplacement responses at Q=0.
Set rfstrs = 1, 2, or 3 (preferably 3).
Set rfelfd = 3.
Set rfatpol and
rfdir to do a full calculation of
phonons at Q=0 (needed because the inverse of
forceconstant tensor is required).
 3 => Both relaxed and clampedion piezoelectric tensors
will be printed out.
The input variable instrflag
should also be set to 1.
Requirements for preceding responsefunction DDB generation
run: Same as for piezoflag=2.
 4 => Calculate the piezoelectric d tensor (relaxed ion).
In order to calculate the piezoelectric d tensor, we need information
of internal strain and elastic tensor (relaxed ion). So we should set
elaflag= 2,3,4, or 5 and
instrflag=1. The subroutine will also do a
check for you, and print warning message without stopping even if
flags were not correctly set.
 5 => Calculate the piezoelectric g tensor (relaxed ion).
In this computation, we need information of internal strain,
elastic tensor (relaxed ion) and dielectric tensor (relaxed ion).
So we should set:
instrflag=1,
elaflag=2,3,4 or 5,
dieflag=3 or 4.
The subroutine will also do a check for you, and print warning message
without stopping even if flags were not correctly set.
 6 => Calculate the piezoelectric h tensor (relaxed ion).
In this calculation, we need information of internal strain and
dielectric tensor (relaxed ion). So we need set:
instrflag=1
and
dieflag=3 or 4.
The subroutine will also do a check for you,
and print warning message without stopping even if flags were not
correctly set.
 7 => calculate all the possible piezoelectric tensors, including
e (clamped and relaxed ion), d, g and h tensors.
The flags should be set to satisfy the above rules from 1 to 6.
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 List of ANADDB input variables
polflag
Mnemonics: POLarization FLAG
Characteristic:
Variable type: integer
Default: 0
If activated, compute polarization in cartesian coordinates,
and update lattice constants and atomic positions in order to perform a structural
optimization at constrained polarization.
More detailed explanation : ANADDB can use the formalism described in
Na Sai et al, PRB 66, 104108 (2002), to perform structural relaxations
under the constraint that the polarization is equal to a value specified by the
input variable targetpol.
The user starts from a given configurationof a crystal and performs
a groundstate calculation of the HellmanFeynman forces and stresses
and the Berry phase polarization as
well as a linear response calculation of the whole matrix of
secondorder energy derivatives with respect to atomic displacement,
strains and electric field.
In case polflag=1, ANADDB solves the linear system of equations
(13)
of the Na Sai paper, and computes new atomic positions (if relaxat=1) and
lattice constant (if relaxstr=1).
Then, the user uses these parameters to perform a new groundstate
and linearresponse calculation. This must be repeated until
convergence is
reached. THe user can also fix some atomic positions, or strains,
thanks to the input variables
natfix,
nstrfix,
iatfix,
istrfix.
In case both relaxat
and relaxstr are 0, while
polflag=1, ANADDB only computes the polarization in cartesian
coordinates.
As described in the Na Sai's paper, it is important
to use the
finite difference expression of the ddk (berryopt=2 or 2)
in the linear response calculation of the effective charges and the
piezoelectric tensor.
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 List of ANADDB input
variables
prtdos
Mnemonics: PRinT the phonon Density Of States
Characteristic:
Variable type: integer
Default : 0
The prtdos variable is used to calculate
the phonon density of states, PHDOS, by Fourier interpolating the interatomic force
constants on the (dense) qmesh defined by ng2qpt.
Note that the variable ifcflag must be set to 1
since the interatomic force constants are supposed to be known.
The available options are:
 0 => no output of PHDOS (default);
 1 => calculate PHDOS using the gaussian method and the broadening defined
by dossmear.
The step of the frequency grid employed to calculate the DOS
can be defined through the input variable dosdeltae.
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 List of ANADDB input
variables
prtfsurf
Mnemonics: PRinT the Fermi SURFace
Characteristic:
Variable type: integer
Default: 0
Only for electronphonon calculations. The available
options are:
 0 => do not write the Fermi Surface;
 1 => write out the Fermi Surface in the BXSF format used by
XCrySDen.
Further comments :
a) Only the eigenvalues for kpoints inside the
Irreducible Brillouin zone are required. As a consequence it is
possible to use kptopt
=1 during the GS calculation to reduce
the computational effort.
b) Only unshifted kgrids that are orthogonal in
reduced space are supported by XCrySDen.
This implies that shiftk
must be set to (0,0,0) during the GS calculation
with nshiftk=1.
Furthermore if kptrlatt
is used to generate the kgrid, all the offdiagonal elements of this
array must be zero.
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 List of ANADDB input
variables
prtmbm
Mnemonics: PRinT ModeByMode decomposition of
the electrooptic tensor
Characteristic:
Variable type: integer
Default: 0
 0 => do not write the modebymode decomposition of the
electrooptic tensor;
 1 => write out the contribution of the individual zonecenter
phonon modes to the electrooptic tensor.
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 List of ANADDB input variables
prtnest
Mnemonics: PRinT the NESTing function
Characteristic:
Variable type: integer
Default: 0
Only for electronphonon calculations.
This input variable is used to calculate the nesting function defined as:
\chi_{nm}(q) = \sum_k \delta(\epsilon_{k,n}epsilon_F) \delta(\epsilon_{k+q,m}\epsilon_F).
The nesting factor is calculated for every point of the kgrid
employed during the previous GS calculation.
The values are subsequently interpolated along the trajectory in q space
defined by qpath, and written in the _NEST
file using the XY format (prtnest=1).
It is also possible to analyze the behavior of the function
in the reciprocal unit cell saving the values in the NEST_XSF file that can be read
using XCrySDen (prtnest=2).
Note that in the present implementation what is really printed to file is
the "total nesting" defined as \sum_{nm} \chi_{nm}(q).
Limitations: the kgrid defined by
kptrlatt
must be orthogonal in reciprocal space,
moreover offdiagonal elements are not allowed, i.e
kptrlatt 4 0 0 0 4 0 0 0 4 is fine while
kprtlatt = 1 0 0 0 1 1 0 1 1 will not work.
 0 => do not write the nesting function;
 1 => write only the nesting function along the qpath in the XY format;
 2 => write out the nesting function both in the XY and in the XSF format.
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 List of ANADDB input
variables
prtsrlr
Mnemonics: PRinT the ShortRange/LongRange
decomposition of phonon FREQuencies
Characteristic:
Variable type: integer
Default: 0
Only if ifcflag=1. The available
options are:
 0 => do not write the SR/LR decomposition of phonon frequencies;
 1 => write out the SR/LR decomposition of the square of phonon frequencies at each qpoint specified
in qph1l.
For details see Europhys. Lett., 33 (9), pp. 713718 (1996).
See also ifcflag,
ifcflag and
dipdip.
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 List of ANADDB input variables
qgrid_type
Mnemonics: Q wavevectors defining a PATH
Characteristic:
Variable type: integer
Default: 0
If qgrid_type is set to 1, the electronphonon part of anaddb will use
the ep_nqpt and ep_qptlist variables to determine
which qpoints to calculate the electronphonon coupling for. This is an alternative
to a regular grid as in the rest of anaddb (using ngqpt).
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 List of ANADDB input variables
qpath
Mnemonics: Q wavevectors defining a PATH
Characteristic:
Variable type: real array qpath(3,nqpath)
Default: qpath(:,:)=0.0
It is used to generate the path along which the phonon band structure and
phonon linewidths are interpolated.
There are nqpath1 segments to be
defined, each of which starts from the end point of the previous one.
The number of divisions in each segment is automatically calculated
inside the code to respect the proportion between the segments.
The same circuit is used for the output of the nesting function if
prtnest=1.
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 List of ANADDB input variables
qph1l
Mnemonics: Q for PHonon List 1
Characteristic:
Variable type:
real array qph1l(4,nph1l)
Default: 0
List of nph1l
wavevectors, at which the phonon frequencies will be interpolated.
Defined by 4 numbers:
the wavevector is made by the three first numbers
divided by the fourth one (a normalisation factor).
The coordinates are defined with respect to the unit vectors
that spans the Brillouin zone. Note that this set of axes
can be nonorthogonal and not normed.
The normalisation factor makes easier the input of wavevector
such as (1/3,1/3,1/3), represented by 1.0 1.0 1.0 3.0 .
The internal representation of this array is as follows :
for each wavevector, the three first numbers are stored
in the array qph1l(3,nph1l), while the fourth is stored
in the array qnrml1(nph1l).
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 List of ANADDB input variables
qph2l
Mnemonics: PHonon List 2
Characteristic:
Variable type:
real array qph2l(4,nph2l)
Default: all 0
List of phonon wavevector directions along which the
nonanalytical correction to the Gammapoint phonon frequencies
will be calculated (for insulators).
Four numbers, as for qph1l,
but where the last one, that correspond to
the normalisation factor, is 0.0
For the anaddb code, this has the meaning that the three previous
values define a direction. The direction is in CARTESIAN
COORDINATES, unlike the nonGamma wavevectors defined in the
first list of vectors...
Note that if the three first numbers are zero, then
the code will do a calculation at Gamma without
nonanalyticities.
Also note that the code automatically set the imaginary
part of the dynamical matrix to zero. This is useful to compute
the phonon frequencies when half of the kpoints has been
used, by the virtue of the timereversal symmetry (which
may induce parasitic imaginary parts...).
The internal representation of this array is as follows :
for each wavevector, the three first numbers are stored
in the array qph2l(3,nph2l), while the fourth is stored
in the array qnrml2(nph2l).
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 List of ANADDB input
variables
qrefine
Mnemonics: Qpoint REFINEment order (experimental)
Characteristic:
Variable type: integer
Default: 0
If qrefine is superior to 1, attempts to initialize a first set of dynamical matrices
from the DDB file, with a qpoint grid which is ngqpt
divided by qrefine (e.g. ngqpt 4 4 4 qrefine 2 starts with a 2x2x2 grid).
The dynamical matrices are interpolated onto the full ngqpt
grid and any additional information found in the DDB file is imposed, before proceeding
to normal band structure and other interpolations. Should implement GaalNagy's algorithm in
PRB 73 014117.
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variables
q1shft
Mnemonics: Q shifts for the grid number 1
Characteristic:
Variable type:
real array q1shft(3,nqshft)
Default: all 0.0
This vector gives the shifts needed to define the coarse qpoint grid.
a) Case nqshft=1
In general, 0.5 0.5 0.5 with the ngqpt's even will give
very economical grids. On the other hand, is it
sometimes better for phonons to have the Gamma point
in the grid. In that case, 0.0 0.0 0.0 should be OK.
For the hexagonal lattice, the above mentioned
quantities become 0.0 0.0 0.5 and 0.0 0.0 0.0 .
b) Case nqshft=2
The two q1shft vectors must form a BCC lattice.
For example, use 0.0 0.0 0.0 and 0.5 0.5 0.5
c) Case nqshft=4
The four q1shft vectors must form a FCC lattice.
For example, use 0.0 0.0 0.0 , 0.0 0.5 0.5 ,
0.5 0.0 0.5 , 0.5 0.5 0.0
or 0.5 0.5 0.5 , 0.0 0.0 0.5 ,
0.0 0.5 0.0 , 0.5 0.0 0.0 (the latter is referred to
as shifted)
Further comments : by using this technique, it is possible
to increase smoothly the number of qpoints, at least
less abruptly than relying on series of grids like
(for the full cubic symmetry):
1x1x1 => (0 0 0)
2x2x2 (shifted) => (.25 .25 .25)
2x2x2 => 1x1x1 + (.5 0 0) (.5 .5 0) (.5 .5 0)
4x4x4 => 2x2x2 + (.25 0 0) (.25 .25 0) (.25 .5 0)
(.25 .25 .25) (.25 .25 .5) (.25 .5 .5)
...
with respectively 1, 1, 4 and 10 qpoints, corresponding
to a number of points in the full BZ of 1, 8, 8 and 64.
Indeed, the following grids are made available :
1x1x1 with nqshft=2 => (0 0 0) (.5 .5 .5)
1x1x1 with nqshft=4 => (0 0 0) (.5 .5 0)
1x1x1 with nqshft=4 (shifted) => (.5 0 0) (.5 .5 .5)
2x2x2 with nqshft=2 => 2x2x2 + (.25 .25 .25)
2x2x2 with nqshft=4 => 2x2x2 + (.25 .25 0) (.25 .25 .5)
2x2x2 with nqshft=4 (shifted) => (.25 0 0) (.25 .25 .25)
(.5 .5 .25) (.25 .5 0)
...
with respectively 2, 2, 2, 5, 6 and 4 qpoints, corresponding
to a number of points in the full BZ of 2, 4, 4, 16, 32 and 32.
For a FCC lattice, it is possible to sample only the Gamma point
by using a 1x1x1 BCC sampling (nqshft=2).
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q2shft
Mnemonics: Q points SHiFTs for the grids 2
Characteristic:
Variable type: real array q2shft(3)
Default: all 0
Similar to q1shft,
but for the series of fine grids.
Note that nqshft
for this series of grids corresponds to 1.
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ramansr
Mnemonics: RAMAN SumRule
Characteristic:
Variable type: integer
Default: 0
Govern the imposition of the sumrule on the Raman tensors.
As in the case of the Born effective charges, the firstorder derivatives
of the linear dielectric susceptibility with respect to an atomic displacement
must vanish when they are summed over all atoms. This sum rule is broken
in most calculations. By putting ramansr equal to 1 or 2, this sum
rule is imposed by giving each atom a part of the discrepancy.
 0 => no sum rule is imposed;
 1 => impose the sum rule on the Raman tensors, giving each
atom an equal part of the discrepancy;
 2 => impose the sum rule on the Raman tensors, giving each
atom a part of the discrepancy proportional to the magnitude of its
contribution to the Raman tensor.
For the time being, ramansr=1 is the preferred choice.
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variables
relaxat
Mnemonics: RELAXation of AToms
Characteristic:
Variable type: integer
Default: 0
If relaxat=1, relax atomic positions during a
structural relaxation
at constrained polarization.
See polflag.
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variables
relaxstr
Mnemonics: RELAXation of STRain
Characteristic:
Variable type: integer
Default: 0
If relaxat=1, relax lattice constants
(lengths/angles) during a structural relaxation
at constrained polarization. See polflag.
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relaxstr
Mnemonics: RELAXation of STRain
Characteristic:
Variable type: integer
Default: 0
If relaxat=1, relax lattice constants (lengths/angles) during a structural relaxation
at constrained polarization.
See polflag.
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rfmeth
Mnemonics: ResponseFunction METHod
Characteristic:
Variable type: integer
Default: 1
Select a particular set of Data Blocks in the DDB.
(PRESENTLY, ONLY OPTION 1 IS AVAILABLE)
 1 => Blocks obtained by a nonstationary formulation.
 2 => Blocks obtained by a stationary formulation.
For more detailed explanations, see abinit_help
If the information in the DDB is available, always use
the option 2. If not, you can try option 1, which is less
accurate.
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rifcsph
Mnemonics: Radius of the Interatomic Force Constant SPHere
Characteristic:
Variable type: real
Default: zero
Cutoff radius for the sphere for
interatomic force constant, see also the alternative nsphere.
If rifcsph= 0 : maximum extent allowed by the grid .
This number defines the atoms for which the
short range part of the interatomic force constants, after
imposition of the acoustic sum rule, will not be put to zero.
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variables
selectz
Mnemonics: SeLECT Z
Characteristic:
Variable type: integer
Default: 0
Select some parts of the effective charge tensor.
(This is done after the application or nonapplication of the ASR for
effective charges). The transformed effective charges are then used for
all the subsequent calculations.
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selectz
Mnemonics: SeLECT Z
Characteristic:
Variable type: integer
Default: 0
Select some parts of the effective charge tensor.
(This is done after the application or nonapplication of
the ASR for effective charges). The transformed effective
charges are then used for all the subsequent calculations.
 0 => The effective charge tensor is left as it is.
 1 => For each atom, the effective charge tensor is made
isotropic, by calculating the trace of the matrix,
dividing it by 3, and using this number in a
diagonal effective charge tensor.
 2 => For each atom, the effective charge tensor is made
symmetric, by simply averaging on symmetrical elements.

Note : this is for analysis the effect of anisotropy
in the effective charge. The result with nonzero selectz
are unphysical.
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variables
symdynmat
Mnemonics: SYMmetrize the DYNamical MATrix
Characteristic:
Variable type: integer
Default: 1 (was 0 before v5.3)
If symdynmat is equal to 1, the dynamical
matrix
is symmetrized before the diagonalization.
This is especially useful when the set of primitive vectors of the unit
cell
and their opposite do not reflect the symmetries of the Bravais lattice
(typical case : bodycentered tetragonal lattices ; FCC and BCC lattices
might be treated with the proper setting of the
brav
variable),
and the interpolation
procedure based on interatomic force constant is used : there are some
slight symmetry breaking effects. The latter can be bypassed by this
additional
symmetrization.
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variables
symgkq
Mnemonics: SYMmetrize the GKk matrix elements for each Q
Characteristic:
Variable type: integer
Default: 1
If symgkq is equal to 1, the electronphonon matrix elements are symmetrized
over the small group of the qpoint they correspond to. This should always be used,
except for debugging or test purposes.
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variables
targetpol
Mnemonics: TARGET POLarization
Characteristic:
Variable type: real targetpol(1:3)
Default: 0.0
Target value of the polarization in cartesian
coordinates and in C/m^2.
See polflag.
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variables
telphint
Mnemonics: Technique for ELectronPHonon
INTegration
Characteristic:
Variable type: integer
Default: 1
Flag controlling the Fermi surface integration
technique used for electronphonon quantities.
 0 = tetrahedron method (no adjustable parameter)
 1 = Gaussian smearing (see elphsmear)
 2 = uniformly weighted band window between ep_b_min and ep_b_max, for all kpoints
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temperinc
Mnemonics: TEMPERature INCrease
Characteristic:
Variable type: real
Default: 2.0
Increment of the temperature in Kelvin, for thermodynamical and elphon
transport properties. See the associated
tempermin
and ntemper variables.
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tempermin
Mnemonics: TEMPERature MINimum
Characteristic:
Variable type: real
Default: 1.0
Lowest temperature (Kelvin) at which the thermodynamical quantities
have to be evaluated. Cannot be zero.
The highest temperature is defined using
temperinc
and ntemper.
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thmflag
Mnemonics: THerMal FLAG
Characteristic:
Variable type: integer
Default: 0
Flag controlling the calculation of thermal quantities.
 When thmflag == 1, the code will compute, using the histogram method :
 the normalized phonon DOS
 the phonon internal energy, free energy,
entropy, constant volume heat capacity
as a function of the temperature
 the DebyeWaller factors (tensors) for
each atom, as a function of the temperature
 the meansquare velocity tensor for each atom, as a function of temperature
 the "average frequency"
as a function of the temperature
(if iavfrq=1)
 When thmflag == 2, all the phonon frequencies for the
q points in the second grid are printed.
 When thmflag == 3, 5 or 7, the thermal corrections to the electronic eigenvalues are calculated.
If thmflag==3, the list of phonon wavevector from the first list is used (with equal weight for all wavevectors in this list),
while if thmflag==5 or 7, the first grid of wavevectors is used,
possibly folded to the irreducible Brillouin Zone if symmetry operations are present,
or if they are recomputed (this happens for thmflag==7).
 When thmflag == 4 or 6, the temperature broadening (electron lifetime) of the electronic eigenvalues is calculated.
If thmflag==4, the list of phonon wavevector from the first list is used (with equal weight for all wavevectors in this list),
while if thmflag==6, the first grid of wavevectors is used, possibly folded to the irreducible Brillouin Zone
if symmetry operations are present or if they are recomputed (this happens for thmflag==8).
WARNING : The use of symmetries for the temperature dependence of the eigenenergies is tricky ! It can only be valid
for the k points that respect the symmetries (i.e. the Gamma point), provided one also averages over the
degenerate states.
Input variables that may be needed if this flag is activated :
dostol,
nchan,
ntemper,
temperinc,
tempermin,
as well as the wavevector grid number 2 definition,
ng2qpt,
ngrids,
q2shft.
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thmtol
Mnemonics: THerModynamic TOLerance
Characteristic:
Variable type: real
Default: 0.05
The relative tolerance on the thermodynamical functions
This number will determine when the series of channel widths
with which the DOS is calculated can be stopped, i.e.
the mean of the relative change going from one grid
to the next bigger is smaller than thmtol.
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use_k_fine
Mnemonics: USE Kgrid FINEr than the coarse kgrid
Characteristic:
Variable type: integer
Default: 0
When set, kptrlatt_fine is suggested to be given. For the present version, both eigenvalues (densergridGKK, obtained from mrggkk with only the GS WFK file) and electronic velocities(GKK files from DDK calculation) are needed. Note that the coarse kgrid must be a subset of the the fine kgrid.
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