[Pw_forum] questions on the acoustic sum rule crystal
Eduardo Ariel Menendez Proupin
eariel99 at gmail.com
Sun Mar 9 15:47:26 CET 2008
Question 1. This question is about the Acoustic Sum Rule in phonon
calculations. Is there a reference to learn about the option zasr='crystal'?
Is 'crystal' always better than 'simple' ?
! zasr : Indicates type of Acoustic Sum Rules used for the Born
! effective charges (character):
! - '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 force-constants matrix)
! - 'crystal': 3 translational asr imposed by optimized
! correction of the IFC (projection).
Question 2. Consider the calculation of the phonon DOS, as in example 06.
The ASR can be imposed in the run of q2r and/or in the run of matdyn, let's
There are four combinations of zasr-asr in q2r an matdyn
1 no no
2 no crystal
3 crystal no
4 crystal crystal
Should there be differences in the final DOS in the combinations 2, 3, and
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