[molpro-user] Oxygen atom

[Kirk Peterson]

Dear Stephen,

the ground state of oxygen atom is ^3P_g  (not u), which has symmetry b1g, b2g, b3g (4, 6, 7).  That's 
probably the source of the problem.

regards,

Kirk


On Jun 3, 2011, at 3:35 PM, Stephen Harrison wrote:

> Dear User mailing list,
> 
> I'm having some problems running a simple calculation on an Oxygen atom.
> From my understanding the ground state of Oxygen is 3P, which become
> degenerate 3B1u,3B2u, 3B3u states in the d2h symmetry molpro uses. I would
> like to calculate this energy, and also the energy of the 3S excited state
> (3Ag in d2h). But I cannot seem to get it to work.
> 
> I have tried the following:
>  {RHF
> wf,8,1,2
>        }
>  {MCSCF
> wf,8,1,2
> }
>  {RHF
> wf,8,2,2
>        }
>  {MCSCF
> wf,8,2,2
> }
>  {RHF
> wf,8,3,2
>        }
>  {MCSCF
> wf,8,3,2
> }
>  {RHF
> wf,8,5,2
>        }
>  {MCSCF
> wf,8,5,2
> }
> 
> In order to get the triplet energies in question (I run it for all 3 of
> the 3Bu's in order to make sure they come out degenerate). But I seem to
> be getting an error message in my output during the first MCSCF run (that
> is asking for the 3Ag state):
> 
> 
> MORE STATES THAN CONFIGURATIONS SPECIFIED:  0  1
> 
> ERROR EXIT
> CURRENT STACK:      MAIN
> 
> 
> I'm not sure how to make the active space larger in order to make the 3Ag
> state available for calculation?
> 
> Thanks very much for any help,
> Stephen Harrison, UCL
> 
> 
> -- 
> Stephen Harrison, Msci.
> stephen.harrison at ucl.ac.uk
> stephen at quantemol.com
> 
> Department of Physics & Astronomy,
> University College London,
> Gower Street,
> London   WC1E 6BT, UK
> 
> Work Tel: +44 (0)20 7679 (ext.3476)
> Mob: 07790 242 874
> 
> 
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