The ABINIT Users Mailing List ( CLOSED )

["Kwan-Woo Lee" <kwlee@ucdavis.edu>]

Dear all,

I got some results about LiBC from ABINT main code and IFC code.
But two results are different?

At Gamma point,  I got the phonon frequencies by using main code with
homogenous Electric perturbation. (e.g., for 001 -direction)

{  Phonon at Gamma, with non-analyticity in the
  direction (cartesian coordinates)  0.00000  0.00000  1.00000
  Phonon frequencies in cm-1    :
- -0.211135D+01  0.477301D+01  0.492702D+01  0.169392D+03  0.169400D+03
-  0.292359D+03  0.292359D+03  0.299125D+03  0.345510D+03  0.345512D+03
-  0.506804D+03  0.509942D+03  0.827816D+03  0.829173D+03  0.114271D+04
-  0.114271D+04  0.115339D+04  0.115339D+04 }

I also got the results by using IFC code with DDB coming from the main
code.  However,
two results are different.
{  Phonon at Gamma, with non-analyticity in the
  direction (cartesian coordinates)  0.00000  0.00000  1.00000
 Phonon frequencies in cm-1    :
- -0.486861D-02  0.000000D+00  0.000000D+00  0.169300D+03  0.169302D+03
-  0.292365D+03  0.292369D+03  0.321218D+03  0.345502D+03  0.345506D+03
-  0.509444D+03  0.655940D+03  0.823731D+03  0.955713D+03  0.114270D+04
-  0.114270D+04  0.115338D+04  0.115338D+04 }

According to Factor group analysis,  the results obtained from main code
look like correct.
(because just 11th and 13th modes are IR active in the 001-direction.)

Why are two results different from?
Is the results coming from IFC code correct?

If there is someone having any idea, please let me know it.

thank you,

Kwan-Woo Lee