[Pw_forum] atomic mass for virtual atom

[Stefano Baroni]

On Apr 25, 2010, at 12:17 PM, Lorenzo Paulatto wrote:

> Replying to message "[Pw_forum] atomic mass for virtual atom" from Payam  
> Norouzzadeh (25/04/10):
>> I need it to insert in input file in front of ATOMIC_SPECIES flag.
> 
> Unless you are doing a molecular dynamics or a phonon calculation the mass  
> is not used.

and, if you do, it would not be a good idea to use the virtual-crystal approximation, but possibly for calculating long-wavelength acoustic modes.

SB

---
Stefano Baroni - SISSA  &  DEMOCRITOS National Simulation Center - Trieste
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