Re: [cclib-devel] etsecs conversions

[Karol L. <kar...@kn...>]

On Wednesday 28 of March 2007 10:45, Noel O'Boyle wrote:
> > But, there seems to be a problem related to the excitation coefficients
> > (which need a tolerance above 0.0005, by the way). Namely, some of the
> > coefficients printed by Gaussian have different signs than the ones
> > printed by GAMESS (observe also that the ones given by Jaguar are
> > consistently with an extra minus compared to GAMESS). This is probably
> > due to the symmetry type (A1, B1, A2, ...). I don't know what the
> > relation is, however, and we should standardize this. Any ideas? Notice
> > that the appropriate new test in testCI.py fails.
>
> As discussed in the other thread, I think we should ignore the signs
> for the purposes of testing. Although I wonder is this related to
> alpha/beta? Should both the alpha and beta orbitals for the same
> transition have the same sign?

I believe the signs before CI coefficients of alpha/beta determinants should 
be the same for singlet states. If I'm not mistaken, for triplets they should 
be reversed.

-- 
written by Karol Langner
Wed Mar 28 15:14:48 CEST 2007