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Reading TPA Output Files

Posted: 03 Dec 2018, 18:15
by tlovell
I recently switched from Dalton to LSDalton because the molecule I was looking at was too big. I ran a very simple TPA calculation on LSDalton, but I'm having trouble reading the output file. I'm interested in the two-photon cross section and the permanent dipole moment change between the ground and excited states. I can't determine if these values are in the output file for the TPA I did or if I have to add extra keywords to get these answers. Any help would be greatly appreciated

Re: Reading TPA Output Files

Posted: 05 Dec 2018, 16:29
by simensr
Dear Terri,

The two-photon cross-sections for linear and polarized light are printed in the output under the line:

``` State No. Exc. Energy Linear pol. Circ. pol.```

Only the transition dipolmoments and Oscillator strengths are printed for the excitations. Permanent dipole moments for excited states can be calculated using the `*DIPOLEMOMENTMATRIX` flag, please take look at the manual for usage.

For large systems you might want to consider using damped response theory, see section `4.8.6 *DAMPED TPA` in the manual for usage and a reference.

Hope this is of help

Re: Reading TPA Output Files

Posted: 05 Dec 2018, 19:34
by tlovell
Thank you for your response! I thought that's where the cross sections were. My trouble now arises from the units. I'm assuming the energy is in a.u., which I can convert to ev or nm and it matches well with my other calculations and literature reports. However, if the cross section units are in a.u and I use the conversion factor where 1 a.u. = 1.896788 x 10^(-50) cm^4s/photon the value is much too large at ~8000 GM when it should be ~400 GM. Am I messing up the units and that's why the values are off? Or could the discrepancy be due to the fact that I didn't use solvent in the calculation, I didn't use the damped response theory and/or there's something else wrong with the input file. Attached is the LSDalton output file of the molecule that I've also analyzed with Dalton and has literature reports, which don't match.