ABINIT Discussion Forums

Hello ABINIT Users
I looked at tutorial but did not find how to use ANADDB to extract or calculate phonon dos.
Could you please help me?
Best regards,Payam Norouzzadeh

prtdos 1
ng2qpt 40 40 40 # or more depending

http://www.abinit.org/documentation/hel ... tml#prtdos

Dear Mverstra
Thank you very much for your reply.
Best regards,Payam Norouzzadeh

Hello ABINIT Users
Does anyone know how ABINIT prints the Phonon density of states? I used prtdos 1 and ng2qpt 20 20 20 but didn't find relevant result in output file. It should be somewhere close to thermodynamical properties but I did not see anything.
Best regards,Payam Norouzzadeh

Dear payam,

have you turned on the thermal flag in your anaddb input file? If not, you should. If you have, send your anaddb input file.

Cheers!

Igor Lukacevic

Dear Lukacevic

Thank you for your attention.
As you can see the thermodynamical flag is on but I can't see any density of states in output file.I will be thankful if you help me.

Best regards,Payam Norouzzadeh



!Flags
ifcflag 1 ! Interatomic force constant flag
thmflag 1 ! Thermodynamical properties flag

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

!Wavevector grid number 2 (series of fine grids, extrapolated from interat forces)
prtdos
ng2qpt 20 20 20 ! sample the BZ up to ngqpt2
ngrids 5 ! number of grids of increasing size
q2shft 3*0.0

!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 40 ! Number of temperatures
temperinc 20. ! Increment of temperature in K for temperature dependency
tempermin 20. ! Minimal temperature in Kelvin

# This line added when defaults were changed (v5.3) to keep the previous, old behaviour
symdynmat 0

Dear payam,

I think that you lack the phonon frequencies calculation in your anaddb input file. Put in eivec, nph1l, qph1l. And yes, by all means, read Phys. Rev. B 51, 8610–8613 (1995).

Cheers!

Igor L.

Dear Lukacevic

Thank you very much for your help and introducing a very useful paper.

Best regards,Payam Norouzzadeh

Dear payam,
in your input file anaddb , add the number 1 in prtdos like this:

prtdos 1

best regards

prtdos produces an additional external file with the DOS, called PHDOS
The copy in the output file for thermal calculations is not convenient and hard to extract. With prtdos you no longer need to run the thermal stuff (although it is very useful thermodynamical information).

Matthieu