CCL: StateAveraged CASSCF calculations

 Sent to CCL by: Yavuz Dede []
I've recently given the very first reference by Ruedenberg at CCL. See
 Also on SA checking work of Jurgen Hinze can help.
Moreover reviews of late Prof. Björn O. Roos, In Adv. Chem. Phys. are nice sources for CASSCF and CASPT2.
As to the weighing factor, there is no exact answer, it needs experimentation; however one usually has no idea about proper weights beforehand and in those cases equal weights for all states is the first choice. But you have to be consistent in SAing among different species; i.e. use the same weight for all.
 BTW 4e in 3o is too small of an active space.
 On 17.11.2011 17:08, Saman Mandegar wrote:
 Sent to CCL by: "Saman  Mandegar" [mandegar_saman[]]
 Dear All,
 I would be very happy to have the ideas about state average calculations in
 CASSCF. I am not pretty sure why state average calculations are done. What is
 the reason? Why it is necessary for excited state computations? And how we
 determine the weighting factor for each state for example in SA3-CAS(4,3)
 calculation? Any help and pointer to literature is greatly appreciated.