Hello,
I did some computations for obtaining the UV-Vis spectra of some compounds. I want to know each lambda max belongs to which electron transfer. In the output file, there are more than one transfer. How can I find which one is the main electron transfer?
As an example:
*****************
Excited State 1: Singlet-A 4.3838 eV 282.82 nm f=0.3462 =0.000
41 -> 43 0.14669
41 -> 45 0.11493
42 -> 43 0.66924
This state for optimization and/or second-order correction.
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Thanks a lot.
Regards,
Ashkan
Hi brother,
Follow the following steps:
1. Optimize the molecule with suitable method and basis set ( check the literature for this) depending on your molecule
2. Then take the optimized geometry from the above step and do TD-DFT calculation
(option: you can include the solvent also) using TD(SINGLETS, NSTATES=10)
3. Compare the calculated absorption spectra (lamda max) with the experiment, taking f >0.0. ( you can view the spectra using gaussview software.
4. Change the method/basis set, if the spectra is not in good agreement with expt..
**** check step 3 , answer for your question
wish you success,
Regards,
Hi brother,
Follow the following steps:
1. Optimize the molecule with suitable method and basis set ( check the literature for this) depending on your molecule
2. Then take the optimized geometry from the above step and do TD-DFT calculation
(option: you can include the solvent also) using TD(SINGLETS, NSTATES=10)
3. Compare the calculated absorption spectra (lamda max) with the experiment, taking f >0.0. ( you can view the spectra using gaussview software.
4. Change the method/basis set, if the spectra is not in good agreement with expt..
**** check step 3 , answer for your question
wish you success,
Regards,
Dear Dr Pal,
Thank you for the time you devoted to this question. I thought too but wasn't sure about the numbers in front of each transition. Thanks very much.
Kind,
Hi Dr. Yousif,
Thanks for your explanation, but I wanted to know after all these steps, how can I find the main electron transfer related to each lambda max. I found my answer thanks to Dr. Pal.
Very kind regards,
Hallo, Ashkan!
Ad the answer of Uttam Pal - this is true for unrestricted calculations (related to spinorbitals).. In the case of restricted formalism (related to orbitals), the square of the coefficients must be doubled.
Best wishes
mb
You may find, in many cases, that several orbitals contribute significantly to the transition. If this is troublesome, you can run a Natural Transition Orbitals analysis, which transforms the orbitals into an equivalent set for which the transition should be a single source orbital and a single destination orbital.
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