effective forces on the unit-cell vectors
Posted: Sun Jul 27, 2014 10:59 am
I wish to know explicitly the derivatives dE/dax, dE/day, dE/daz, etc., where E is the total energy and (ax,ay,az) is a unit-cell lattice vector. Can these be deduced from the printed stress tensor obtained using ISIF=3? Can they be deduced from the subsequent printed changes in the unit-cell vectors after the first geometry optimization cycle?