This document lists and provides the description of the name (keywords) of the input variables to be used in the main input file of the abinit code, to perform electron-phonon calculations.
Govern the imposition of the Acoustic Sum Rule (ASR) in phonon calculations. Same meaning as the corresponding anaddb variable.
Set the treatment of the Charge Neutrality requirement for the effective charges. Same meaning as the corresponding anaddb variable.
This variable is mandatory when optdriver==7. It defines the number of divisions in the (homogeneous) q-mesh used to generate the DDB file. See also the description of the getddb input variable.
Only relevant when optdriver==7. It defines the shift in the q-mesh used to generate the DDB file, which is defined by the ddb_ngqpt input variable. See shiftk for more information on the definition.
This variable defines the treatment of the dipole-dipole interaction. Same meaning as the corresponding anaddb variable
This variable can be used to change the value of the Fermi level when performing electron-phonon calculations with optdriver==7. This variable has effect only if set to a non-zero value. See also eph_extrael.
This variable defines the energy window around the Fermi level used for e-ph calculations (optdriver = 7). Only the states located in the energy range [efermi - eph_fsewin, efermi + eph_fsewin] are included in the e-ph calculation.
Related input variables: eph_intmeth, eph_fsmear, eph_extrael and eph_fermie.
This variable defines the gaussian broadening used for the integration over the Fermi surface when eph_intmeth == 1.
This variable defines the technique for the integration on the Fermi surface of electron-phonon quantities.
1 for Gaussian technique with broadening factor eph_fsmear. 2 for tetrahedron method.
See also eph_fsewin, eph_extrael and eph_fermie.Average electron-electron interaction strength, for the computation of the superconducting Tc using Mc-Millan's formula.
This variable activates the interpolation of the first-order variation of the self-consistent potential in the electron-phonon code. If eph_nqgpt_fine differs from [0, 0, 0], the code will use the Fourier transform to interpolate the DFPT potentials on this fine q-mesh starting from the irreducible set of q-points read from the DDB file. This approach is similar to the one used to interpolate the interatomic force constants in q-space. If eph_ngqpt_fine is not given, the EPH code uses the list of irreducible q-points reported in the DDB file (default behavior).
NB - this does not work yet. This variable can be used to turn on the calculation of transport quantities in the eph module of abinit. Value of 1 corresponds to elastic LOVA as in the PRB by Savrasov and Savrasov.
Select the integration technique for computing the phonon DOS and the Eliashberg function a2fF(w).
1 for Gaussian scheme (see also ph_smear).
2 for tetrahedron method (no other input is needed but requires at least 4 q-points in the BZ)
This variable is used in conjunction with ph_nqpath and ph_qpath to define the q-path used for phonon band structures and phonon linewidths. It gives the number of points used to sample the smallest segment in the q-path specified by ph_qpath.
This integer defines the number of points in the ph_qpath array.
This variable defines the number of shifts in the q-mesh used for the phonon DOS and for the Eliashberg functions (see ph_ngqpt). If not given, the code assumes a Gamma-centered mesh. The shifts are specified by ph_qshift.
This array gives the shifts to be used to construct the q-mesh for computing the phonon DOS and the Eliashberg functions (see also ph_nqshift. If not given, a Gamma-centered mesh is used.
The gaussian broadening used for the integration of the phononDOS and the Eliashberg function. See also ph_intmeth and ph_ngqpt.
The step used to generate the (linear) frequency mesh for the phonon DOS and the Eliashberg function. The extrema of the mesh are automatically computed by the code.
Print the phonon density of states. It is activated by default when optdriver==7.
Print a bxsf file (Xcrysden format) with the (interpolated) phonon frequencies computed of the q-mesh determined by ph_ngqpt. The file can be use to visualize isosurfaces with Xcrysden or other similar tools supporting the bxsf format. Note that the (dense) q-mesh must be Gamma-centered, shifted meshs are not supported by Xcrysden. This variable requires optdriver==7.
If symdynmat is equal to 1, the dynamical matrix is symmetrized before the diagonalization (same meaning as the corresponding anaddb variable). Note that symdynmat==1 will automatically enable the symmetrization of the electron-phonon linewidths.