IFC and unit of freq in PHDOS

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IFC and unit of freq in PHDOS

Postby ganck » Wed Feb 13, 2019 12:41 pm

i would to get the IFC in ifcinfo.out so that I can analyse IFC myself.

Code: Select all
!Input file for the anaddb code. Analysis of the SiO2 DDB

 ifcflag   1     ! Interatomic force constant flag
 ifcout    -1
 thmflag   1     ! Thermodynamical properties flag
 enunit 2

!Wavevector grid number 1 (coarse grid, from DDB)
  brav    1      ! Bravais Lattice : 1-S.C., 2-F.C., 3-B.C., 4-Hex.)
  ngqpt   9  9  9   ! Monkhorst-Pack indices
  nqshft  1         ! number of q-points in repeated basic q-cell
  q1shft  3*0.0

!Effective charges
  chneut   1     ! Charge neutrality requirement for effective charges.

!Interatomic force constant info
  dipdip  1      ! Dipole-dipole interaction treatment

!Wavevector grid number 2 (series of fine grids, extrapolated from interat forces)
  prtdos 1
  ng2qpt   30 30 30  ! sample the BZ up to ngqpt2
  ngrids   5         ! number of grids of increasing size
  q2shft   3*0.0
  prt_ifc 1

!Thermal information
  nchan   1250   ! # of channels for the DOS with channel width 1 cm-1
  nwchan  5      ! # of different channel widths from this integer down to 1 cm-1
  thmtol  0.120  ! Tolerance on thermodynamical function fluctuations
  ntemper 10     ! Number of temperatures
  temperinc 20.  ! Increment of temperature in K for temperature dependency
  tempermin 20.  ! Minimal temperature in Kelvin

anaddb < xfiles7

runs well, but zero file size for ifcinfo.out

0 Feb 13 18:36 ifcinfo.out

Sorry I do not understand.

Also I would like to get the unit of freq not to be Hartree


but no matter what enunit I used, the freq in PHDOS is still Hartree, and not 1/cm that I want.
Posts: 2
Joined: Wed Feb 13, 2019 12:29 pm

Re: IFC and unit of freq in PHDOS

Postby ganck » Wed Feb 20, 2019 12:16 pm

The json files of Petretto et al. ph_dos on 1521 compounds [Scientific Data
2018] seem to have x having cm^{-1} for Frequency, and 1/eV for the phonon density of states.
Posts: 2
Joined: Wed Feb 13, 2019 12:29 pm

Re: IFC and unit of freq in PHDOS

Postby ebousquet » Thu Feb 21, 2019 6:31 pm

Dear ganck,
I think only Hartree units are printed in the DOS file... The eunit flag of anaddb is only for the main output (https://docs.abinit.org/variables/anaddb/#enunit).
Regarding the IFC printing, are you sure ifcout -1 is permitted (https://docs.abinit.org/variables/anaddb/#ifcout)?
best wishes,
Posts: 303
Joined: Tue Apr 19, 2011 11:13 am
Location: University of Liege, Belgium

Re: IFC and unit of freq in PHDOS

Postby mverstra » Mon Apr 01, 2019 1:54 pm

Regarding the output units, you are correct that they are not implemented systematically. Some files, but mainly the output+log were implemented a long time ago, and more recent developments (probably the PHDOS file as well) are only in Hartree a.u. This is not a big deal to post-process, and the main guarantee is that abinit uses Ha a.u. internally systematically, and usually for output as well.
Matthieu Verstraete
University of Liege, Belgium
Posts: 637
Joined: Wed Aug 19, 2009 12:01 pm

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