Page 1 of 1

selective relaxation of cell parameters

Posted: Thu Jan 17, 2008 7:45 am
by rgc
Hi

is it possible to relax one particular cell parameter (e.g. cz) and leave the others (ax, ay, az, bx, by, bz, cx, cy) fixed?

of course it is always possible to build a E vs cz curve, with everything else constant, then fit to a polynomial and find the minimum. But I am wondering whether there is an automatic way of doing this constrained relaxation in vasp... Do "F F T" kind of flags work for cell parameters?

thanks!

selective relaxation of cell parameters

Posted: Mon Jan 28, 2008 10:33 am
by admin
no, you can either keep the cell shape completely fixed (only V varying, but c/a and the angles are kept constant) or relax all cell parameters simutaneously (shape relaxed completely) if you want to do it automatically (by using the appropriate ISIF)