[Pw_forum] Phonon calculation at high pressure

[Bipul Rakshit]

Dear PWscf users,
I am doing phonon calculation for ScAs in B1(NaCl) and B2 (CsCl) structure.
For B1 structure, all the phonon modes comes +ve in the entire brillouin
zone.
For B2 structure, I first get the minimum energy by running relax and then
scf. and then I step over to phonon calculation, as in B1 structure.

But for B2 structure I am getting many -ve frequencies. Although ScAs (B2)
structure is stable at some high pressure, so do i have to set some pressure
in the system and then I have to do the phonon calculation?

In simple words, how can i do the phonon calculation for ScAs (B2) structure
which is structure at high pressure?


-- 
Bipul Rakshit
PhD Student,
Barkatullah University,
Bhopal 462026,
MP, India
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