[Pw_forum] Why acoustic sum rule correction affcted my optical mode a lot?

Paolo Giannozzi p.giannozzi at gmail.com
Tue Nov 10 09:30:42 CET 2015

2015-11-09 20:29 GMT+01:00 liyincumt at gmail.com <liyincumt at gmail.com>:

the optical modes should not be affected by the acoustic sum rule
> correction. However, in my case, the low-frequency optical modes are
> affected a lot  by the acoustic sum rule correction. Even high frequency
> optical modes are affected by the acoustic sum rule correction to some
> extent. Does it mean that I am using a wrong ASR. My current ASR is
>  'zero-dim'.

first of all, try 'simple'. If the situation doesn't improve: your
calculation might not be sufficiently converged (tr2_ph parameter too large)

Paolo Giannozzi, Dept. Chemistry&Physics&Environment,
Univ. Udine, via delle Scienze 208, 33100 Udine, Italy
Phone +39-0432-558216, fax +39-0432-558222
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