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How to deal with fractional occupation ?
Posted: Tue Nov 16, 2010 3:08 am
by mazuju
Hi,
In compound ABC, A atoms and B atoms are at the same position, and half occupied.
How to write the position information in input file?
Best，
Ma ZJ
Re: How to deal with fractional occupation ?
Posted: Tue Nov 16, 2010 11:36 am
by jzwanzig
The simple but very approximate way is to use the Virtual Crystal Approximation: see input variable mixalch and related variables. I think this approach is only allowed in abinit with norm-conserving pseudopotentials, not with PAW. The more "realistic" approach but more time-consuming is to make a supercell of your structure and simply populate sites by hand with the different atoms in the right ratio.
Re: How to deal with fractional occupation ?
Posted: Tue Nov 16, 2010 1:40 pm
by mazuju
jzwanzig wrote:The simple but very approximate way is to use the Virtual Crystal Approximation: see input variable mixalch and related variables. I think this approach is only allowed in abinit with norm-conserving pseudopotentials, not with PAW. The more "realistic" approach but more time-consuming is to make a supercell of your structure and simply populate sites by hand with the different atoms in the right ratio.
Thank you for your advice.