[Pw_forum] Exceptionally large charge density cut-off

[Paolo Giannozzi]

Subhradip Ghosh wrote:

> Thanks Paolo. Does that mean one should not use USPP for phonon calcs at
> all? I guess it varies from case to case.

this is also my guess. For sure it works in some cases, but in other
cases USPP (especially those produced by Vanderbilt's code, according
to my limited experience) are so difficult to use in phonon calculations
that you do not gain anything with respect to ordinary PPs

> This is bit strange as to why USPP would fail for phonons. In that case,
> the applicability of USPP would be really limited.

unfortunately it is. Ideas welcome.

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