[Pw_forum] question about pseudo and lowdin analysis

[Paolo Giannozzi]

Cyrille Barreteau wrote:

> How the inclusion or not of p wavefunction affects the quality of the 
> pseudo?

if the pseudopotential is the same and you just add a p atomic orbital
to the PP file, nothing will change in the calculation (apart from a
small difference in slef-consistency  because the starting point is
slightly different). The Lowdin charges will change, as they always
do since they depend upon the set of atomic orbitals used for the
projection. A difference of 1/3 of an electron is rather surprising,
but I don't see any reason to think that there is anything wrong in
the algorithm. Likely, yet another indication that "atomic" charges
should be taken with a (rather large) grain of salt

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