[Pw_forum] How to generate pseudo of atoms on a partially occupied position using virtual.x ?

[degironc]

the simplest way to generate the pseudopotential you are want is to 
modify (it should be trivial) virtual.x code so that it accepts only one 
pseudo in input and multiplies it by x.
However the quality of VCA depends on the assumption that the two mixed 
potentials are similar...
It is unlikely that this is the case for an oxygen and a vacancy.
The proper way to deal with vacancies is within the supercell aproach. 
What kind of properties are you interested in ?
stefano

ruizhi zhang wrote:

> Dear all：
> I want to study a system in which oxygen atoms are on a partially 
> occupied position. So I need to generate a 'virtual' potential of 
> oxygen using Virtual Crystal Approximation . As has been discussed in 
> the forum, using virtual.x in upftools/
> new pseudopotential = (1-x)V1+xV2
> However, in my case V1 is pseudo of Oxygen and V2 is a vacancy, and I 
> do not know how to deal with it.
> Can I generate a pseudo of Oxygen specifying the Z valance=0 ? (Maybe 
> it is a stupid idea) and use this as the pseudo of vacancy?
> Thank you very much in advance.
> Best regards
> ruizhi zhang
>
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