[molpro-user] Problem with CASPT2 energies for Excited states

[Tolga Karsili]

Hi,

I have done many CASPT2 calculations on phenol so I know the theory pretty 
well. Try state average with the first five singlet states (3 of symmetry 1 
(s0,s1 and s3) and 2 of symmetry 2 (s2,s4).

also include the 3s Rydberg orbital centered on the oxygen in your active 
space in order to describe the Rydberg-Valence mixing at the vertical 
Frack-Condon region on the s2 state, since this is the orbital one excites 
into at the vFC.

So in general you casscf and caspt2 step should look like this:

 {casscf
 occ,23,7
 closed,20,0
 natorb,,ci
 wf,50,1,0;state,3
 wf,50,2,0;state,2
 }

 {rs2c,shift=0.5
 occ,23,7
 closed,20,0
 natorb,,ci
 state,1,1
 wf,50,1,0
 }

 {rs2c,shift=0.5
 occ,23,7
 closed,20,0
 natorb,,ci
 state,1,2
 wf,50,1,0
 }

 {rs2c,shift=0.5
 occ,23,7
 closed,20,0
 natorb,,ci
 state,1,1
 wf,50,2,0
}

Try this.

Best wishes,
Tolga

--On 31 October 2012 12:00 +0000 molpro-user-request at molpro.net wrote:

> Problem with CASPT2 energies for Excited states



----------------------
Tolga Karsili
Laser Group
School of Chemistry
University of Bristol
Tolga.Karsili at bristol.ac.uk