ABINIT Discussion Forums

Dear Sir,
I want to ask a question about dealing NLO calculation with "Analysis of the DDB" in the link:
https://docs.abinit.org/tutorial/nlo/,
(Linear and non-linear responses from density functional perturbation theory (DFPT))
which is the fifth step with the command "anaddb < tnlo_5.files > out5".

• tnlo_5.in
  tnlo_5.out
  tnlo_4.ddb.out
  tnlo_5_thm_dummy
  tnlo_5_gkk_dummy
  tnlo_5_ep_dummy
  tnlo_5_ddk_dummy

The tnlo_5.in is that:

• rfmeth 1
  enunit 0
  eivec 1
  chneut 2
  selectz 0
  # Flags
  #*******
  dieflag 1
  ifcflag 0
  thmflag 0
  nlflag 1
  elaflag 3
  piezoflag 3
  instrflag 1
  # Nonlinear response calculation
  #*******************************
  ramansr 1
  alphon 1
  prtmbm 1
  # Wavevector list number 1
  **************************
  nph1l 1
  qph1l 0.0 0.0 0.0 1.0 #
  # Wave vector list no. 2
  #***********************
  nph2l 1
  qph2l 0.0 0.0 1.0 0.0

The error is that :

• --- !ERROR
  src_file: anaddb.F90
  src_line: 436
  mpi_rank: 0
  message: |
  Cannot find block corresponding to non-linear optical susceptibilities in DDB file
  ...

I have calculated the official examples for AlAs, no errors appeared. Then, I choose LiIO3 as my first start to calculate the NLO properties. But always with this error. Hope for your help!

Detail input is submitted as attachments! Looking forward to your reply!

Dear cocoinsky,
This is because you have forgotten to update the input flag rfatpol according to the number of atom you have in your new unit cell. AlAs has 2 atoms but you have more atoms in your case (10). The code is thus complaining that some derivative terms are missing because you asked to do atomic displacement perturbations with atom 1 and 2 only.
Best wishes,
Eric