[CPMD-list] negative USPP augmentation charges

[Jaroslaw Panek]

Dear CPMD'ers,

while generating and testing various Vanderbilt pseudopotentials in
CPMD3.7, we have encountered (very rarely) negative values of mean
augmentation charges on halogen atoms (ranging from -0.2 to -0.5).
While this does not seem to me to contradict rules along which USPPs are
generated, and moreover uspp7.3.4 diagnostics seem all OK, I would like to
know your opinion if this behaviour can affect some parts of CPMD
calculations? We have observed no abnormalities, but are there certain
functionals or other parts of code that can misbehave encountering
negative USPP augmentation charges?

With greetings from sunny Wroclaw,

Jaroslaw Panek
Faculty of Chemistry, University of Wroclaw
ul. F. Joliot-Curie 14, 50-383 Wroclaw, Poland