[molpro-user] FCI calculations for Be and B, charged and/or triplet

[Peter Knowles]

You tripped over a bug in the FCI code which did not properly handle the 
case of zero beta-spin electrons. We have fixed this for future 
versions; you can get by for a 2-electron triplet by using rcisd instead 
of fci.

Peter

Bastiaan J. Braams wrote:
> Dear Molpro users,
> 
> I'm trying to do FCI calculations for small systems: single atoms and
> XH diatom molecules where X is at most oxygen.  Does anyone have
> advice about these three sample cases, for which a molpro 2002.6
> calculation fails at the FCI command: B+ triplet, Be+ doublet, and Be
> triplet?  Here are the three input files.
> 
> ***,SP ENERGY FOR B1+ triplet
> memory,84,m
> geomtyp=xyz
> geometry
> nosym
>  1
>     null
>  B      0.00000000   0.00000000   0.00000000
> end
> basis=aug-cc-pvtz
> rhf;wf,charge=1,sym=1,spin=2
> fci
> ---
> 
> ***,SP ENERGY FOR Be1+ doublet
> memory,84,m
> geomtyp=xyz
> geometry
> nosym
>  1
>     null
>  Be     0.00000000   0.00000000   0.00000000
> end
> basis=cc-pvtz
> rhf;wf,charge=1,sym=1,spin=1
> fci
> ---
> 
> ***,SP ENERGY FOR Be1 triplet
> memory,84,m
> geomtyp=xyz
> geometry
> nosym
>  1
>     null
>  Be     0.00000000   0.00000000   0.00000000
> end
> basis=cc-pvtz
> rhf;wf,charge=0,sym=1,spin=2
> fci
> ---
> 
> Bas Braams
> --
> Bastiaan J. Braams
> braams at mathcs.emory.edu
> Emory University, Atlanta, GA

-- 
Prof. Peter J. Knowles
School of Chemistry, Cardiff University, Main Building, Park Place, 
Cardiff CF10 3AT, UK
Telephone: +44 29208 79182 Fax: +44 2920874030
Email KnowlesPJ at Cardiff.ac.uk  WWW 
http://www.cardiff.ac.uk/chemy/staff/knowles.html