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Re^7: Help needed with the Transition density matrix determination and analysis....

Alex Granovsky

Dear Siddheshwar,

I'll answer you when I'll have more time. The explanation is somewhat lengthy.

Kind regards,
Alex Granovsky

On Fri Sep 26 '14 2:48pm, Siddheshwar Chopra wrote
>Dear Alex Sir,
>I would be really grateful if you could throw some light on the transition density matrix calculation. Is it possible to determine the matrix from TDDFT output file? IF yes then I would attach one file. Kindy let me know Sir.

>Kind Regards,
>On Sat Sep 20 '14 8:10am, Siddheshwar Chopra wrote
>>Dear Pavlo Sir and Alex Sir,
>>Thank you so much for the useful information. Alex sir I am really happy to know that it is possible to find TDM from PUNCH file (from TDDFT calc.). I would request you to elaborate the process for the same. Right now I dont have any punch file with me. Can you explain with the help of any punch file? Once that is clear, I will look for the program.
>>Also, Sir I found that transition dipole moment matrix in the TDDFT o/p file is of the size NSTATE X NSTATE. Can you explain how to analyse this? I find the x,y,z data corresponding to an i,j element. Does the magnitude of this dipole moment = sqrt(x^2+y^2+z^2)? Any help would be welcomed. If I plot this graph, what could be conveyed from this?

>>Kind Regards,
>>On Sat Sep 20 '14 1:28am, Alex Granovsky wrote
>>>Dear Siddheshwar,
>>>Dear Pavlo,

>>>internally, Firefly (and other QC codes) uses one-particle TDM to
>>>compute such properties like transition dipole moments/dipole
>>>velocities and oscillator strengths. These is no option at present
>>>to print out a computed one-particle TDM.


>>>for TDDFT, one-particle TDM can be recovered using an information
>>>found in the punch file. You will need to write small Fortran
>>>or C program for this.

>>>Kind regards,
>>>Alex Granovsky
>>>On Thu Sep 18 '14 8:37pm, Pavlo Solntsev wrote
>>>>TDM you can get for MCSCF/XMCQDPT jobs. I am not sure about DFT. By default TDM is not available in the output file. Probably, Alex may answer your question regarding DFT/TDDFT level of theory.

>>>>On Thu Sep 18 '14 1:36pm, Siddheshwar Chopra wrote
>>>>>Dear Pavlo,
>>>>>I read an article which used the Transition density matrix analysis. According to it, transition densities represent coherent electronic transitions between ground and electronically excited states.

>>>>>Some references:
>>>>>a) S. Mukamel, S. Tretiak, T. Wagersreiter, V. Chernyak, Science1997, 277,781 787;
>>>>>b) S. Tretiak, K. Igumenshchev, V. Chernyak,Phys. Rev. B2005,71, 033 201;
>>>>>c) S. Tretiak, S. Mukamel, Chem. Rev.2002, 102, 3171 3212;
>>>>>d) S. Tretiak, V. Chernyak, S. Mukamel,Chem. Phys. Lett.1996, 259,5561;
>>>>>e) K. I. Igumenshchev, S. Tretiak, V. Y. Chernyak,J. Chem. Phys.2007,127, 114902;
>>>>>f) Y. H. Li, C. A. Ullrich, Chem. Phys.2011, 391, 157 163.

>>>>>The transition-density matrix analysis helps in pointing out the section of structure/molecule from where the electronic transition mainly occurs.
>>>>>Also I found a paper which describes the relation between transition dipole moment and transition density.
>>>>>a) Mengtao Sun,Jianing Chen and Hongxing Xu, THE JOURNAL OF CHEMICAL PHYSICS 128, 064106 2008.

>>>>>In general transition density contains information about the spatial location of the excitation.

>>>>>Kind Regards,
>>>>>On Thu Sep 18 '14 5:01am, Pavlo Solntsev wrote
>>>>>>Dear Siddheshwar.

>>>>>>Could you please explain me what Transition density matrix stands for?


>>>>>>On Wed Sep 17 '14 9:45am, Siddheshwar Chopra wrote
>>>>>>>Dear Users,
>>>>>>>I wish to know about the determination of Transition density matrix. How do we extract it from the o/p data? Do we need to mention any special command to get the same? If no, then how to search for it in the o/p file? What all we can infer using it? Someone please throw some light on it.

>>>>>>>Kind Regards,

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