[Pw_forum] about atom occupied factor

[Paolo Giannozzi]

On May 31, 2009, at 20:35 , Javier Camarillo Cisneros wrote:

>     The occupied factor between .1 to 1 is the factor of times that  
> a atom
> appears on one position, shared with other atom.
>     For example, I need specified two different atom (Fe 25% and Ti  
> 75%)
> to the same position at one octahedral site on Aurivillius crystal.
>      This crystal is formed to 196 atoms, so is not possible create 4
> times the lattice to incorporate at the same time the 3 Ti and the  
> 1 Fe.

than you need virtual crystal approximation. I don't know how  
satisfactory
VCA can be in this case, though

Paolo
---
Paolo Giannozzi, Dept of Physics, University of Udine
via delle Scienze 208, 33100 Udine, Italy
Phone +39-0432-558216, fax +39-0432-558222