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Re^9: How to check for acceptance of Kasha's rule from TDDFT data...?

Siddheshwar Chopra

Dear users,
I need few things to be clarified regarding the absorption and emission calculations. They are:
1)  Say from absorption calc. I have the the data: s0->s6 with f= 0.045,s0->s8 with f= 0.075 etc. Here the absorption seems stronger for the latter.. Now say I have the emission data:  s6->s0 with f= 0.005,s9->s0 with f= 0.095 and s12->s0 with f= 0.10.
My question is that abs. data shows a strong absorption for s6 state. Now is it possible to get a low f value for the s6 to s0 emission transition?
Is it possible to get higher f value for say s12, which had a very low value in absorption transition? How should we then figure out the dominant emission transition?
Should we pick up the lamda-max from absorption calc. and also its transition(say s0 to s6) and then search for emission data for all transitions lower than this s6 level (s5,s4....s1)? and then picking the one with highest f value.. This would be the emission wavelength.

Please someone help with this. I hope I made my point clear.

Kind Regards,

On Sun Oct 5 '14 11:56am, Siddheshwar Chopra wrote
>Dear Alex,
>Yes I will surely do that. However I would be really glad if you could just say that I am thinking on the right lines or not. Can we this way guess whether a transition is fluorescent or not?

>Kind Regards,

>On Sat Oct 4 '14 7:12pm, Alex Granovsky wrote
>>Dear Siddheshwar,

>>I strongly recommend you to read a good book on photochemistry and a textbook on quantum chemistry.

>>Kind regards,
>>Alex Granovsky

>>On Thu Oct 2 '14 11:03am, Siddheshwar Chopra wrote
>>>Dear Users,
>>>Is there a way to find out lifetimes of excited states using TDDFT? If yes can somebody explain how to do it? I just know we can use heisenberg's uncertainity pple for that.
>>>Also if it is possible to find tau, then can we point out from these values, whether an excited state will be resonsible for fluorescence or not?

>>>Kind Regards,


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