How make POSCAR if atom take a half site

Question on input files/tags, interpreting output, etc.

Please check whether the answer to your question is given in the VASP online manual or has been discussed in this forum previously!

Moderators: Global Moderator, Moderator

Post Reply
Message
Author
wei
Newbie
Newbie
Posts: 2
Joined: Wed Jun 22, 2005 3:22 pm

How make POSCAR if atom take a half site

#1 Post by wei » Wed Jun 22, 2005 11:01 pm

Hello everyone,

I have a problem for making POSCAR for free energy calculation. A compound ABC4 crystalized cubic structure with fm-3m symmetry (z=4). The atom position is A:4a; B:4b; C:32f (1/2 occupancy).
Who can tell me how should I do if I want to calculate total energy?
Last edited by wei on Wed Jun 22, 2005 11:01 pm, edited 1 time in total.

admin
Administrator
Administrator
Posts: 2922
Joined: Tue Aug 03, 2004 8:18 am
License Nr.: 458

How make POSCAR if atom take a half site

#2 Post by admin » Fri Jun 24, 2005 12:04 pm

If in a crystal only half of the sites of a sublattice are occupied, you have to construct a larger supercell, containing at least one occupied C site and one vacancy (site not occupied) in sublattice C. Please be aware that this sublattice is periodically repeated, i.e. it corresponds to an ordered structure.
Last edited by admin on Fri Jun 24, 2005 12:04 pm, edited 1 time in total.

Post Reply