Re: [cclib-devel] CI and TDDFT

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

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.

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:

 STATE #   2  ENERGY =    4.928436 EV
 OSCILLATOR STRENGTH =    0.051448
 SYMMETRY OF STATE   =    BU
        DRF    COEF       OCC      VIR
        ---    ----       ---      ---
         34 -0.749876     34  ->   36
         35 -0.220121     35  ->   36
         67 -0.070269     32  ->   37
         70 -0.625220     35  ->   37
        139 -0.033687     34  ->   39

Noel

On 14/11/2007, Noel O'Boyle <bao...@gm...> wrote:
> Dear all,
>
> 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.
>
> The policy I am following is that for every type of calculation, the
> sum of the squares of the etsecs values is close to 1...
>
> Noel
>