[Pw_forum] How to set nbnd value for berry phase calculations?

[Paolo Giannozzi]

Lim Chiang Huay, Freda wrote:

> In such cases, is there a guideline how we should set the nbnd value
> to calculate the berry phase?

I think that the berry phase can be calculated only in insulators.
You should use spin polarization (nspin=2) and fix the total
magnetization (tot_magnetization=1, I guess). Then you can use
any number of bands, as long as they are in sufficient number
to accommodate all electrons (the less bands, the quicker the
calculation, of course). No warranty.

P.
-- 
Paolo Giannozzi, Democritos and University of Udine, Italy