A question about the Berry-phase polarization in VASP
Posted: Mon Jul 25, 2011 1:43 am
I am wondering how VASP calculate the k gradient of KS orbitals, which is a part of the final formula of Berry-phase theory of polarization. Does VASP calculate it in numerical way? I think that is very expansive, or maybe it is calculated differently. Please help me to understand.
Thanks in advance.
Thanks in advance.