[molpro-user] Radical Cation Wavefunction
Tony Stüker
tony.stueker at fu-berlin.de
Sun Apr 17 11:18:49 CEST 2016
Hi Alan
The state symmetry is determined by the direct product[1] of all
electrons of the system.
You will see that the direct product of a closed shell system is always
the lowest irrep in the character table.
Examples for a c2v system:
Closed shell system: ^1A1
Dublett state with one unpaired electron in a mo with b1 symmetry, the
state symmetry would be ^2B1
Triplett state with two unpaired electrons in mos with a1 and b1
symmetry: A2 x B1 = B2
Hope that helps a little bit.
Cheers, Tony
[1] https://www.staff.ncl.ac.uk/j.p.goss/symmetry/Products.html
On 04/16/2016 02:00 PM, MD Simulation wrote:
> Hi Joachim,
>
> Thanks for your reply, it's very helpful.
>
> How do I know the state symmetry before the calculation? I would like
> to read more about how to determine the proper symmetry, are there
> specific terms I could look up for the wave function symmetry?
>
> I've read this section of the quickstart manual several times:
> https://www.molpro.net/info/2012.1/doc/quickstart/node11.html
> I've also read:
>
> https://www.molpro.net/info/2012.1/doc/manual/node33.html#sec:symmetry
> https://www.molpro.net/info/2012.1/doc/manual/node34.html
>
>
> Again, thank you for your help,
> Alan
>
>
>
>
> On Sat, Apr 16, 2016 at 6:27 AM, Hans-Joachim Werner
> <werner at theochem.uni-stuttgart.de
> <mailto:werner at theochem.uni-stuttgart.de>> wrote:
>
> Hi,
> the Hartree-Fock program at least tries to find the lowest state and
> to determine the state symmetry automatically. But this is based on
> orbital energies and there
> is no guarantee that the correct state is always found. The meaning
> of the state symmetries is explained in the manual, see also the
> quickstart manual for examples. For example, in a linear molecule
> oriented along the z-axis, a Sigma^+, state has symmetry 1, Pi_x,
> Pi_y (symmetries 2,3), Sigma^- symmetry 4, Delta_{x^2-y^2} symmetry
> 1, Delta_{xy} symmetry 4 (but note that some of these states require
> more than 1 Slater determinant, and then mcscf muust be used for a
> proper description).
> Best regards
> Joachim Werner
> ---
> Prof. Dr. Hans-Joachim Werner
> Institute for Theoretical Chemistry
> University of Stuttgart
> Pfaffenwaldring 55
> D-70569 Stuttgart
> Tel: +49 711 / 685 64400
> Fax: +49 711 / 685 64442
> email: werner at theochem.uni-stuttgart.de
> <mailto:werner at theochem.uni-stuttgart.de>
>
>
> > Am 15.04.2016 um 14:56 schrieb MD Simulation
> <mdsimulationgroup at gmail.com <mailto:mdsimulationgroup at gmail.com>>:
> >
> > Hello Molpro Users,
> >
> > I'm very new Molpro but have used NWChem and Gaussian quite a
> bit. I'm attempting to use CCSD(T) on a radical cation organic
> compound. My question is, how necessary is it to set the
> wavefunction symmetry and occupied orbitals (I'm not certain how to
> determine either of those) in the WF card and OCC card? In NWChem
> or Gaussian I would simply set the charge (equal to 1) and
> multiplicity (equal to 2), so in this case will I get the correct
> results by simply using:
> >
> > """
> > wf,charge=1,spin=1
> > """
> >
> > Thanks for the help. And as a side note, Molpro is really fast!
> >
> > Cheers,
> > Alan
> > _______________________________________________
> > Molpro-user mailing list
> > Molpro-user at molpro.net <mailto:Molpro-user at molpro.net>
> > http://www.molpro.net/mailman/listinfo/molpro-user
>
>
>
>
> _______________________________________________
> Molpro-user mailing list
> Molpro-user at molpro.net
> http://www.molpro.net/mailman/listinfo/molpro-user
>
More information about the Molpro-user
mailing list