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["Bo Qiu" <200210qb@gmail.com>]

Dear Users and developlers,

I'm trying to calculate Phonon DOS for Bi2Te3 which has a rhombohedral structure, space group 166.

I followed the tutorial on Response functions #2 step by step:
1. generate k points using script similar to trf2_2.in, 
2. copied k points from trf2_2.out and copy them to trf2_1.in as  kpoints.
3. run trf2_1.in to get DDBs.
4. mrgddb
5. anaddb trf2_7.in 

However, when I got to the 5th step, I got following error out of the log file of trf2_7:
====================================
Calculation of the interatomic forces

-begin at tcpu      0.090  and twall      0.114 sec
 ewald9 : ERROR -
  The determinant of the dielectrix matrix, detdlt=    0.000000E+00 is smaller than 1.0d-6.
  The use of the dipole-dipole model for interatomic force constants is not possible.
  It is likely that you have not treated the electric field perturbations,
  because you not are dealing with an insulator, so that
  your dielectric matrix was simply set to zero in the Derivative DataBase.
  Action : set the input variable dipdip to 0 .

 leave_new : decision taken to exit ...
====================================

Actually I had specified one data set to treat electric field perturbation at gamma point in the trf2_1.in file. Then I went back to check trf2_1.out, I found there were warnings in output of every data set (corresponding to every qpoint):

chkph3 : WARNING -
  The dynamical matrix was incomplete : phonon frequencies may be wrong ...

However, I checked with the trf2_1.out of the tutorial AlAs case, for exactly the same specifications of input variables, there were not such warnings in the output file at all. 

I've tried for quite a while but still cannot get a clue, could you please help me with this problem? I appreciate your kind help!

-- 
Thanks and Best Wishes.

Sincerely yours,
Bo Qiu
http://web.ics.purdue.edu/~qiub/homepage/