[molpro-user] RSPT2 for an open-shell degenerate state

[Victor G. Solomonik]

Dear Wenli,

On April 25, 2010, at 4:01 you wrote:

> To the best of my knowledge there is not a multi-reference
> method/program to detecte the super-symmetry at the MRCI/PT2 stage
> so the degeneracy can not be preserved strictly. The situation in
> MRPT2 may be much worse than in MRCI, especially when there are
> active d or Rydberg orbitals (I have tried the MRPT2 methods in
> MOLPRO, MOLCAS, and GAMESS-US).
 
The GAMESS-US MCQDPT2/CASSCF code yields (with a symmetry being
imposed) a perfect degeneracy for Ni^3+ 4F state, as well as for
other numerous examples of degenerate atomic and molecular states with
active d or f orbitals which I have ever tried before.

-- 
Best regards,
 Victor                          mailto:sol at isuct.ru