[ADF-LIST] Transition dipole contributions

Erik van Lenthe vanlenthe at scm.com
Mon Jan 23 10:12:08 CET 2017

Dear Adam Ashwell,

For a given excitation the major MO -> MO transitions are given.
However, there are many MO -> MO transitions that are not printed, but 
which will also contribute to the transition dipole moment.
The sum of all contributions, printed and non-printed, is -.26198 in the 
z-direction.

The list of Major MO -> MO transitions is given for analysis purposes.
It is clear that the 59a1->60a1, with weight 0.9735, is the most 
important MO -> MO transition that contributes to the excitation.
However, one needs many more contributions of other MO -> MO transitions 
with low weights to get a reliable transition dipole moment.

Best regards,
Erik van Lenthe
SCM


You wrote:
> Dear all,
>
> I’m trying to do some analysis on TDDFT results involving contributions to transition dipole moments from single particle transitions. In the excitations section of the .out file, the total dipole moments in the x, y, and z directions is listed. However, these values are not the same as those that come from summing up the contributions from single particle transitions. For example, for one of my calculations the total transition dipole moment is given here:
>
>   no.  E/eV          f                       mu (x,y,z)
>   ------------------------------------------------------------------
>     1  1.9961     0.33564E-02   0.0000       0.0000     -0.26198
>
> But the single particle transition dipole moment contributions in the z direction sum to -0.1992:
>
>       Nr.          orbitals           weight        contributions to
>                                       (sum=1) transition dipole moment
>                                                x       y       z
>
>
>       1:  59a1      ->  60a1         0.9735  0.0000  0.0000 -1.4612
>       1:  47b2      ->  49b2         0.0045  0.0000  0.0000  0.2272
>       1:  47b1      ->  49b1         0.0045  0.0000  0.0000  0.2225
>       1:  37a2      ->  38a2         0.0036  0.0000  0.0000  0.2170
>       1:  47b2      ->  48b2         0.0028  0.0000  0.0000  0.1866
>       1:  47b1      ->  48b1         0.0027  0.0000  0.0000  0.1856
>       1:  57a1      ->  60a1         0.0019  0.0000  0.0000  0.1997
>       1:  59a1      ->  62a1         0.0013  0.0000  0.0000  0.1945
>       1:  47b2      ->  50b2         0.0012  0.0000  0.0000 -0.0577
>       1:  47b1      ->  50b1         0.0012  0.0000  0.0000 -0.0577
>       1:  59a1      ->  64a1         0.0004  0.0000  0.0000 -0.0063
>       1:  37a2      ->  41a2         0.0003  0.0000  0.0000 -0.0294
>       1:  46b1      ->  49b1         0.0002  0.0000  0.0000 -0.0200
>
> I figure that the value given earlier (-.26198) is correct, as when I look at these the transition dipole values in that section correlate better with oscillator strength.
>
> My question is, why are these different? If the earlier value is correct, what is the significance of the values listed alongside the single particle transitions? They are not always different in the same direction either – sometimes the sum from the single particle transition section is larger, rather than smaller, so it doesn’t seem to be a bizarre unit issue.
>
> Thanks,
> Adam Ashwell
> _______________________________________________
> ADFlist mailing list
> ADFlist at scm.com
> https://lists.scm.com/mailman/listinfo/adflist


More information about the ADFlist mailing list