[molpro-user] (no subject)

[Jacky LIEVIN]

Hi Gerry,

Vibrational calculations are indeed calculated with symmetry=nosym for all multiconfigurational methods. All C2v states of interest are thus to be calculated within the C1 subgroup in which all states belong to the same symmetry (symmetry 1). This means that for calculating an excited state you must perform a state averaged CASSCF calculation including all states below (whatever their symmetry) and an MRCI calculations on the same number of states. You can then define the state number (let say n) on which the frequencies will be calculated using in the frequency program variable= energy(n) or variable=energd(n) (including Davidson correction).
Of course frequencies must be calculated at the equilibrium geometry corresponding to the same state averaged procedure.

best,

Jacky

> Le 9 août 2017 à 17:02, Hoffman, Gerald <GHOFFMAN at edinboro.edu> a écrit :
> 
> I would like to determine the vibrational frequencies of three excited states of a molecule on which I'm performing MRCI calculations.  The molecule has C2v symmetry, and the three states all belong to different symmetry designations.
> 
> However, when I attempt to perform a vibrational frequency calculation, Molpro admonishes me for not designating the calculation as NOSYM.  Is it possible to perform a vibrational frequency calculation in MRCI on excited electronic states of definite symmetry?  If so, how?
> 
> Thank you.
> 
> Gerry Hoffman
> 
> Gerald J. Hoffman, Ph. D.
> 
> Associate Professor of Chemistry
> 
> Edinboro University of Pennsylvania
> 
> 230 Scotland Road
> 
> Edinboro, PA 16444
> 
>  
> 814-732-2813
> 
>  
> ghoffman at edinboro.edu <mailto:ghoffman at edinboro.edu>
>  
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_____________________________________
Prof. Jacky Liévin
Service de Chimie Quantique et Photophysique
Université Libre de Bruxelles, CPi 160/09
50 av F.D. Roosevelt
B-1050 Bruxelles
Belgium
Tel: +32-2-650 4089
Fax: +32-2-650 4232
_____________________________________

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