suggest unit test

[yuan-gist]

Since VASP can provide WSWQ, the overlap matrix elements, could you consider adding unit tests to compare with VASP calculations?

I tried this, but cannot reproduce the VASP WSWQ.

[kylebystrom]

Sorry for the delayed reply. I have not used WSWQ before; does this refer to the overlap of the wavefunctions with the wavefunctions of another calculation at some perturbed configuration coordinate? Also, it would be helpful to have a better understanding of the problem. Do you have a minimal reproducing example of VASP and pawpyseed giving different values for what should be equivalent quantities? Also, how large is the error?

I will try my best to help but probably cannot make any significant contributions until March.