It is the asr that apply this. You can get the explanation in dynmat.f90
! asr character indicates the type of Acoustic Sum Rule imposed
! - 'no': no Acoustic Sum Rules imposed (default)
! - 'simple': previous implementation of the asr used
! (3 translational asr imposed by correction of
! the diagonal elements of the dynamical matrix)
! - 'crystal': 3 translational asr imposed by optimized
! correction of the dyn. matrix (projection).
! - 'one-dim': 3 translational asr + 1 rotational asr
! imposed by optimized correction of the dyn. mat. (the
! rotation axis is the direction of periodicity; it
! will work only if this axis considered is one of
! the cartesian axis).
! - 'zero-dim': 3 translational asr + 3 rotational asr
! imposed by optimized correction of the dyn. mat.
! Note that in certain cases, not all the rotational asr
! can be applied (e.g. if there are only 2 atoms in a
! molecule or if all the atoms are aligned, etc.).
! In these cases the supplementary asr are cancelled
! during the orthonormalization procedure (see below).
! Finally, in all cases except 'no' a simple correction
! on the effective charges is performed (same as in the
! previous implementation).
Jin Zelin
School of Energy & Power Engineering
Huazhong University of Science & Technology
1037 Luoyu Road, Wuhan 430074, P.R. China
------------------ Original ------------------
From: "??????";<[email protected]>;
Send time: Saturday, Mar 14, 2015 5:31 PM
To: "PWSCF Forum"<[email protected]>;
Subject: Re: [Pw_forum] Help, about the phonon calculation of GaN.
Dear Paolo,
Thank your for your reply. Now, I want to know how to apply Acoustic Sum
Rule correction? Thank you in advance!
Best Regards!
Yu Hailin
At 2015-03-04 20:28:40, "Paolo Giannozzi" <[email protected]> wrote:>On
Tue, 2015-03-03 at 17:24 +0800, ?????? wrote:>>> 1. The frequences of freq ( 1)
~freq ( 3) should be zero, why>> there are
not?>>http://www.quantum-espresso.org/faq/phonons/#7.2>>> 2. The hexagonal GaN
is belong to C_6v (6mm) point group, why our>> result is C_3v (3m) point group
as above
shown?>>http://www.quantum-espresso.org/wp-content/uploads/Doc/pw_user_guide/node19.html#SECTION000600190000000000000>>Paolo>--
> Paolo Giannozzi, Dept. Chemistry&Physics&Environment, > Univ. Udine, via
delle Scienze 208, 33100 Udine, Italy> Phone +39-0432-558216, fax
+39-0432-558222 >>_______________________________________________>Pw_forum
mailing list>[email protected]>http://pwscf.org/mailman/listinfo/pw_forum
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