[Pw_forum] about the number of Projectors in uspp

[Lorenzo Paulatto]

Wei Zhou ha scritto:
> dear all users
>               I feel puzzled about the number of Projectors in uspp ,
how this value is determine.

Dear Wei Zhou,
the number of projectors is chosen arbitrarily by the psudopotential
author in order to trade off accuracy and efficiency. Usually you take two
projectors per each ultrasoft wavefunction and only one for
norm-conserving ones (they can coexist in the same pseudo).

More projectors are added only in some specific cases, as far as I know
for reproducing more accurately high-energy (normally empty) bands.

regards

-- 
Lorenzo Paulatto
SISSA  &  DEMOCRITOS (Trieste)
phone: +39 040 3787 511
skype: paulatz
www:   http://people.sissa.it/~paulatto/




----------------------------------------------------------------
  SISSA Webmail https://webmail.sissa.it/
  Powered by SquirrelMail http://www.squirrelmail.org/