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Re^4: Can't figure out how to find emission spectra of Benzene...

Siddheshwar Chopra

Dear Pavel,
Your suggestions have always been valuable to me. I will start working on your files and will let you know in case I need your help.

Kind Regards,

On Wed Jun 11 '14 4:17pm, Pavlo Solntsev wrote
>I attached example how to do Luminescence calculation for porphyrin molecule. For more detailed information please, check manual AND this forum.

>Salvation model has not been programmed for TDDFT+gradient. Therefore, optimization of the excited state was done without solvent correction. However, this correction was included into spectra calculation.

>Very often geometry optimization of the excited state brakes a true molecular symmetry. Keep this in mind.

>For more complex systems state of interest may be different, not S1. It is especially true if you have a donor group in your molecule and thus HOMO....HOMO-x belong to the donor, but you are looking for emission within porphyrin core. In such case you need identify the state of interest based on TDDFT(ground state) and knowledge.

>Good luck.

>On Tue Jun 10 '14 10:16pm, Siddheshwar Chopra wrote
>>Dear Alex,
>>I searched a lot on this forum regarding the same. What you told is right and I know these too. But I want to step by step how to optimize  the S1? say for  benzene.
>>And then how should I determine S0--> S1 (optimized)?
>>Please help me stepwise. Any i/p files would be of great help.. I have noted from TDDFT calc of benzene that orbitals 17-24 are most dominant ones. How do I proceed next?

>>Kind Regards,

>>n Tue Jun 10 '14 7:43pm, Alex Granovsky wrote

>>>for emission spectra you need to optimize S1 geometry and then compute
>>>vertical transition from S0 to S1 at optimized geometry of S1.

>>>Kind regards,
>>>Alex Granovsky
>>>On Sat Jun 7 '14 9:10pm, Siddheshwar Chopra wrote
>>>>Dear Firefly users,
>>>>I need some real help in determining the emission spectra (S1--->SO*) of benzene.
>>>>I have understood till optimizing the ground state and then obtaining the vertical transition from SO--->S1*...
>>>>Please help me now what I should do next? Any i/p files would be welcomed.

>>>>Kind Regards,

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