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Re^3: How to check for acceptance of Kasha's rule from TDDFT data...?

Siddheshwar Chopra
sidhusai@gmail.com


Dear Pavlo,
That is some real relief... Actually the same under study is a doped one. Sir please read my last message and answer them. The picture of Emission process is unclear to me, with regard to the firefly calculations. The ISSTATE=1 is ENSURING that we are finding a transitions from S1 only..Is it correct?
So now SPECIFICALLY about the emission calculations::: What are these EXCITED STATE 1, 2 and so on (depending on NSTATE vaue)? I mean are these the S0 vibrational levels now (because now we are studying de-excitation)? If yes, then how exactly do I find the emission wavelength? Is the analysis similar to the absorption spectra analysis then? I mean using osc. str. etc.? Please guide me.
Also if Kasha's rule holds good, then do I get a high osc. str. at 1st excited state itself in the o/p file?

Regards,

On Thu Sep 25 '14 1:42am, Pavlo Solntsev wrote
----------------------------------------------
>Kasha's rule doesn't always work. For example, if you have redox active group near chromophore.

>Try to figure out absorbtion--emission situation for a porphyrin.

>-Pavlo.
>
>
>
>On Wed Sep 24 '14 9:11pm, Siddheshwar Chopra wrote
>--------------------------------------------------
>>Dear users,
>>Somebody please help me in understanding this concept. I need to know that by setting istate =1 in emission spectra calculation, I am actually setting or calculating the de-excitation from the S1 state. Am I correct? If yes, then the TDDFT o/p gives me a set of transitions possible for every excited state (set by variable nstate).What are these nstates now? Do they hold any significance in S1-->S0 transition? Do we mean that these are the vibrational levels of S0 level? Please explain this in the light of kasha's rule.
>>I am worried because I am unable to point out the emission wavelength. Please help me Alex Sir and Pavlo Sir. Please help me in analysing the emission calculations.

>>Kind Regards,
>>
>>
>>n Tue Sep 23 '14 12:21pm, Siddheshwar Chopra wrote
>>---------------------------------------------------
>>>Dear Users,
>>>Please have a look at the attached file which contains a table describing the contributions/transitions from first four states only for both the absorption and emission calculations. For absorption, I understand that the final state can be any of the excited states which has highest osc. strength. Am I right? But my doubt is regarding kasha's rule... If you see the emission data, the first excited state has a very low oscillator strength of 0.004 (HOMO-->LUMO(97 at 2678.9 nm. However the higher states have a better contribution than this state. So please tell me how to analyse this properly. To my knowledge emission wavelength is around 600-730nm.
>>>I would be grateful for any help.

>>>Kind Regards,


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