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<TITLE>RE: [molpro-user] How to input singlet Pi state ?(1)</TITLE>
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<P><FONT SIZE=2>Dear All,<BR>
<BR>
this is an illustrative example singlet open shell systems. The remaining question is: how do you calculate the vibrational frequencies? Apparently these have to be done numerically and without symmetry, but I don't know how to get the right state-averaged wavefunction without it. Any insights would be much appreciated.<BR>
<BR>
juan<BR>
<BR>
<BR>
-----Original Message-----<BR>
From: owner-molpro-user@molpro.chem.cf.ac.uk on behalf of Jacky LIEVIN<BR>
Sent: Fri 07-Oct-05 10:15<BR>
To: molpro-user@molpro.net<BR>
Subject: [molpro-user] How to input singlet Pi state ?(1)<BR>
<BR>
Sorry, the input of my previous mail doesn't work without changing<BR>
occ,5,2,1 by occ,5,2,2<BR>
The correct input is thus:<BR>
<BR>
basis=avtz<BR>
r=1.23<BR>
Geometry={angstrom;<BR>
C<BR>
O,C,r<BR>
}<BR>
multi;<BR>
occ,5,2,2<BR>
closed,4,1,1<BR>
wf,14,2,0<BR>
wf,14,3,0<BR>
print,orbitals,civector<BR>
<BR>
Jacky<BR>
<BR>
<BR>
<BR>
>It would be better to use a state average MCSCF calculation<BR>
>including both components of the singlet pi state. You will get in<BR>
>this way the correct two fold degeneracy of the pi state. A pi state<BR>
>of a linear molecule splits into a B1 and a B2 irreducible<BR>
>representations of the C2v point group used by molpro for performing<BR>
>the calculation. B1 and B2 corresponds to symmetries 2 and 3 of<BR>
>molpro. The correct input is thus:<BR>
>basis=avtz<BR>
>r=1.23<BR>
>Geometry={angstrom;<BR>
>C<BR>
>O,C,r<BR>
>}<BR>
>multi;<BR>
>occ,5,2,1<BR>
>closed,4,1,1<BR>
>wf,14,2,0<BR>
>wf,14,3,0<BR>
><BR>
>good luck<BR>
><BR>
>Jacky<BR>
><BR>
><BR>
>>The exact input should be in your case:<BR>
>><BR>
>>basis=avtz<BR>
>>r=1.23<BR>
>>Geometry={angstrom;<BR>
>>C<BR>
>>O,C,r<BR>
>>}<BR>
>>multi;<BR>
>>occ,5,2,1<BR>
>>closed,4,1,1<BR>
>>wf,14,2,0<BR>
>><BR>
>>Peter<BR>
>><BR>
>><BR>
><BR>
> Jacky Liévin<BR>
>Service de Chimie Quantique et Photophysique<BR>
>CPi 160/09<BR>
>50 av F.D. Roosevelt<BR>
>B-1050 Bruxelles<BR>
>Belgium<BR>
>Tel: +32-2-650 4089<BR>
>Fax: +32-2-650 4232<BR>
>_________________<BR>
><BR>
> no attachments have been sent<BR>
<BR>
--<BR>
----------------------------------------------------<BR>
Jacky LIEVIN<BR>
Universite Libre de Bruxelles<BR>
Laboratoire de Chimie Quantique et Photophysique:<BR>
atomes, molécules et atmosphères<BR>
Cpi 160/09<BR>
50 Av. F.D. Roosevelt<BR>
B-1050 Bruxelles<BR>
Belgium<BR>
Tel: 32-2-650 4089<BR>
Fax: 32-2-650 4232<BR>
----------------------------------------------------<BR>
<BR>
<BR>
<BR>
</FONT>
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