The ABINIT Users Mailing List ( CLOSED )

["Aldo Humberto Romero" <aromero@qro.cinvestav.mx>]

I agree with Mathieau.. did you check if your frequencies
from the anaddb analysis in Gamma match the values obtained
from the electric field perturbation?.. I am sure they will not and
you will have to use the ones obtained from the electric field
perturbation calculation.

-aldo.

> Dear Aldo, dear Mathieau
>
>> was the data for the Gamma point obtained from anaddb ? or the
>> frequencies were obtained in a different calculation with polarization.
> Yes, from anadbb, and corrected (as in tutorial)
> All frequencies were obtained in 1 calculation run.
>
> Maybe I should use `rfelfd3 = 1` ?
>
>
> I posted anadbb input and (some) abinit input below.
>
>> Did you use the anaddb keyword to symmetrize the ifc's?..
> If you mean the parameter 'symdynmat' , I didn't specify it and used v.
> 5.2.3, so I guess it was 0. (at least that's what the online manual says).
>
> Will it help to switch it on?
>
> Cheers Marcel
>
>
>
> Attachment:
> ==========
>
> !!!Anaddb input file
>
> !Input file for the ifc code. Analysis of the AlAs DDB
>
> !Flags
>   ifcflag   1     ! Interatomic force constant flag
>
> !Wavevector grid number 1 (coarse grid, from DDB)
>    brav    4      ! Bravais Lattice : 1-S.C., 2-F.C., 3-B.C., 4-Hex.)
>    ngqpt   6  6  4   ! Monkhorst-Pack indices
>    nqshft  1         ! number of q-points in repeated basic q-cell
>    q1shft  0.0 0.0 0.0
>
> !Effective charges
>       asr   1     ! Acoustic Sum Rule. 1 => imposed asymetrically
>    chneut   1     ! Charge neutrality requirement for effective charges.
>
> !Interatomic force constant info
>    dipdip  1      ! Dipole-dipole interaction treatment
>    ifcana  1      ! Analysis of the IFCs
>    ifcout 50      ! Number of IFC's written in the output, per atom
>    natifc  4      ! Number of atoms in the cell for which ifc's are
> analysed
>     atifc  1 2 3 4     ! List of atoms
>
>
>
> ###abinit input file
>
>
>     ndtset   24
> #Set 1 : ground state self-consistency
>
>    getwfk1   0            # Cancel default
>    kptopt1   1            # Automatic generation of k points, taking
>                           # into account the symmetry
>      nqpt1   0            # Cancel default
>    tolvrs1   1.0d-18      # SCF stopping criterion (modify default)
>    rfphon1   0            # Cancel default
>
> #Q vectors for all datasets
>
> #Complete set of symmetry-inequivalent qpt chosen to be commensurate
> # with kpt mesh so that only one set of GS wave functions is needed.
> #Generated automatically by running GS calculation with kptopt=1,
> # nshift=0, shiftk=0 0 0 (to include gamma) and taking output kpt set
> # file as qpt set. Set nstep=1 so only one iteration runs.
>
>       nqpt   1            # One qpt for each dataset (only 0 or 1 allowed)
>                           # This is the default for all datasets and must
>                           #  be explicitly turned off for dataset 1.
>>snipped 24 q-points<
>
> #Set 2 : Response function calculation of d/dk wave function
>
>      iscf2   -3         # Need this non-self-consistent option for d/dk
>    kptopt2   2          # Modify default to use time-reversal symmetry
>    rfphon2   0          # Cancel default
>    rfelfd2   2          # Calculate d/dk wave function only
>    tolvrs2   0.0        # Cancel default for d/dk
>    tolwfr2   1.0d-22    # Use wave function residual criterion instead
>
> #Set 3 : Response function calculation of Q=0 phonons and electric field
> pert.
>
>    getddk3   2          # d/dk wave functions from last dataset
>    kptopt3   2          # Modify default to use time-reversal symmetry
>    rfelfd3   3          # Electric-field perturbation response only
>
> #Sets 4-10 : Finite-wave-vector phonon calculations (defaults for all
> datasets)
>
>     getwfk   1          # Use GS wave functions from dataset1
>     kptopt   3          # Need full k-point set for finite-Q response
>     rfphon   1          # Do phonon response
>    rfatpol   1 4        # Treat displacements of all atoms
>      rfdir   1 1 1      # Do all directions (symmetry will be used)
>     tolvrs   1.0d-8     # This default is active for sets 3-10
>
>>snipped the rest<
>
>


-- 
Dr. Aldo Humberto Romero
FULL PROFESSOR CINVESTAV - Unidad Queretaro
Libramiento Norponiente 2000
Real de Juriquilla, CP 76230, Qro, Queretaro
Mexico

Phone: + 52 442 441 4909
Fax: + 52 442 441 4938
Email: aromero@qro.cinvestav.mx
WWW:  qro.cinvestav.mx/~aromero