[Columbus] MCSCF in COLUMBUS

[Hans Lischka]

Dear Spiridoula,

In a FCI there are no orbitals to optimize since the energy is invariant 
under unitary transformations. The final reason of the breaking is the 
fact that there are no virtual orbitals, as you suspected. Actually, a 
simple energy calculation would be sufficient. I am not sure from the 
error message where the calculations really broke. Did it do so at the 
very beginning or did go beyond the energy calculation? Could yo send us 
the mcscfls file from the WORK directory?

The alternative is (as Felix wrote) to use the ciudg program and perform 
the FCI calculation with a corersponding reference space and zero 
excitations into the virtual (non-existent) space.

Ron and Thomas, do you have other suggestions?

Best regards, Hans

On 3/1/2017 8:46 PM, Spiridoula Matsika wrote:
> Dear Columbus friends,
>
> I am trying to run a benchmark calculation. The system is HeH+ and I am
> setting up an MCSCF to act as FCI. So the active space contains all the
> orbitals in the basis set. But the calculation always fails. I have
> tried different versions of Columbus, different basis sets, etc. but
> nothing seems to work. The error I get is:
>
>  *** error *** orthot: na,nb=         0         1
>  bummer (fatal):orthot: argument error                      0
>
>
> Is there any reason that the MCSCF in COLUMBUS will not work if there
> are no virtual orbitals and all orbitals are included in the CAS?
>
> Thank you,
> Spiridoula Matsika
>
>
>
> Spiridoula Matsika
> Professor of Chemistry
> Department of  Chemistry
> Temple University
> 1901 N.13th Street
> 242 Beury Hall
> Philadelphia, PA 19122
>
> Phone: 215 204 7703
> Fax: 215 204 1532
> smatsika at temple.edu <mailto:smatsika at temple.edu>
>
>
>
>
>
>
>
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