Re: [cclib-devel] CI and TDDFT

[Noel O'B. <bao...@gm...>]

On 15/11/2007, Karol Langner <kar...@kn...> wrote:
> On Wednesday 14 November 2007 11:37, Noel O'Boyle wrote:
> > I'm wondering whether either of you know whether the etsecs from a
> > restricted calculation of triplet excited states is likely to add to 1
> > (after squaring). I'm getting:
> >
> >    ---------------------------------
> >      R-TDDFT CALCULATION CONVERGED
> >    ---------------------------------
> >  NUMBER OF USED VECTORS / MAX =  49 / 200
> >  NUMBER OF ITERATIONS   / MAX =   6 / 100
> >  NUMBER OF SINGLE EXCITATIONS =   875
> >  NUMBER OF ATOMIC ORBITALS    =  60
> >  NUMBER OF TOTAL ELECTRONS    =          70.0035208
> >
> >           -------------------
> >           TRIPLET EXCITATIONS
> >           -------------------
> >
> >  STATE #   1  ENERGY =    3.027228 EV
> >  OSCILLATOR STRENGTH =    0.000000
> >         DRF    COEF       OCC      VIR
> >         ---    ----       ---      ---
> >          35 -1.105383     35  ->   36
> >          69 -0.389181     34  ->   37
> >         103 -0.405078     33  ->   38
> >         137  0.252485     32  ->   39
> >         168 -0.158406     28  ->   40
> >
> > The squares add to 1.63 or so.
>
> I've never seen a coefficient larger than one - I don't know what that means.
> Notice the oscilator strength is zero (or really very small).
>
> Can you attach the entire output file (i think only the singlet version is in
> teh trunk)? Also, how does this compare to Gaussian output?
I'll check in the triplet one.

> From my
> experience, GAMESS is buggy in some places when it comes to excitations. I've
> had some problems using soem of the CIS options.
>
> > It's not a big deal for users of cclib as we just extract whatever
> > figure is given here. Still, if anyone has any insight it would be
> > good to know. For comparison, here is a similar transition for the
> > SINGLET EXCITATIONS:
>
> True, although it would be good to know what's happening and maybe warn the
> user. I routinely use scripts to check output files for errors/warnings and
> generally strange output. This might be a good thing to add to cclib n the
> future.
>
> > > The handling of the etsecs is likely to have changed for CI due to my
> > > latest checkin. I hope this is not a problem. I am currently trying to
> > > standardise the values of etsecs for all calculations (using tests),
> > > but am only halfway. I need to carry out some TD-DFT calculations on
> > > unrestricted calculations and sort these out at the same time as
> > > handling the CI calculations.
>
> I'll have closer look over the weekend.
I'll try to sort it out by then, so you that you can doublecheck what
I've done...

> Karol
>
> --
> written by Karol Langner
> Thu Nov 15 14:38:10 EST 2007
>