Computing vibration frequencies while working in sub-symmetry

Subject:

if B is 1s22s22p1, what is Li?

Passfield:

Comments:
: Dear Molcas team and Molcas users, : Is it possible to calculate vibration frequencies when working in sub-symmetry? I do not understand the following message: : **************************************** : * WARNING!! : * Elements in the E^[2] matrix small!! : * The calculation might diverge. : * : * Check your active space!!!! : * : * Make sure degenerate orbitals do not : * belong to different spaces. : * Note that no LR code can handle : * 2.0d0 occupancy in active orbitals!! : **************************************** : As I get this when I calculate the vibration frequencies of ML6 in a D2h (sub-)symmetry (active space = d-orbitals), but not when I compute such frequencies for -for instance- benzene in a Cs (sub-)symmetry (active space = pi-system)... (degenerate orbitals in different symmetries, 2.0d0 occupancy of some orbitals, etc. in both cases) : Thank you in advance, : Regards, : Julien.