Posted by Roland Lindh on February 24, 2008 at 20:54:51:
In Reply to: Re: EXCITED STATE CASSCF/CASPT2 posted by Ignacio on February 21, 2008 at 09:25:53:
Hi,
as you do a state average CASSCF the GS energy will be higher. That is natural. The other effect is more subtle. An excited state might stabilize other orbitals than those which the GS stabilized. This problem occur normally we a full valence CI is not possible. I urge you to look at the active orbitals with GV in the both cases. This will most likely help you to understand the problem. In your case it seems like there are two orbitals are symmetry related and the for the SA-CASSCF only one of those has been included in the active space. Hence the distorted final geometry.
Take care,
-roland