Go to the example posted on Gaussian

http://www.gaussian.com/g_tech/g_ur/k_scrf.htm

For orbital contribution you must see coefficients in front orbitals reported at every excitation. Example:

Excited State 1: Singlet-A 4.0595 eV 305.42 nm f=0.0000 =0.000

34 -> 37 0.67614

34 -> 39 -0.20151

Here is reported excitation energy, oscillator strength, electronic state and orbital contributions. 34->37 (HOMO->LUMO+2) is the main excitation because of the largest coefficient.

For charge transfer states, you could observe a big increasing in the dipole moment as compared to the ground state, or you can sum atomic charges in the donor and the acceptor to be respectively +1 and -1 for that specific excited state you analyze.

I do not think the former analysis to be possible with DFT; indeed you should use TD-DFT. C-DFT may be another option but I am not sure if it is available in G09; I do not think so.

Finally, better use CAM-B3LYP functional with at least double zeta basis set.

You can use TDDFT technique to calculate spectra and look at contributions of different orbitals to transitions. Then you can analyse composition of orbitals or their shape in some visualizer like gaussview. I'm not expert in gaussian, though you can refer to on-line manual

Go to the example posted on Gaussian

http://www.gaussian.com/g_tech/g_ur/k_scrf.htm

For orbital contribution you must see coefficients in front orbitals reported at every excitation. Example:

Excited State 1: Singlet-A 4.0595 eV 305.42 nm f=0.0000 =0.000

34 -> 37 0.67614

34 -> 39 -0.20151

Here is reported excitation energy, oscillator strength, electronic state and orbital contributions. 34->37 (HOMO->LUMO+2) is the main excitation because of the largest coefficient.

For charge transfer states, you could observe a big increasing in the dipole moment as compared to the ground state, or you can sum atomic charges in the donor and the acceptor to be respectively +1 and -1 for that specific excited state you analyze.

I do not think the former analysis to be possible with DFT; indeed you should use TD-DFT. C-DFT may be another option but I am not sure if it is available in G09; I do not think so.

Finally, better use CAM-B3LYP functional with at least double zeta basis set.

TD-DFT calculation by G09 is good to calculate the UV spectra and orbital contribution. You can also use PCM model if you have your absorption spectra in any solvent for better understanding.  You can do  HOMO LUMO calculation for the orbital contribution and charge transfer. 

TDDFT is a single excitation theory. It typically include single excitation from an occupied orbital to virtual orbital with symmetry labelled. Orbital composition corresponds to the single determinant dominated by the single excitation relative to reference state.

Can any body provide me a step-wise manual with an example of molecule ? He may send me this document in my mail ..........

[email protected]

Even i want to make a collaboration with him/her.

Consider that i have G03....not G09.

hi Gourisankar Roymahapatra you can read the user guide gaussian , read TD keyword & SCRF keyword !

Thanks, Mr. Morteza

Can i get ur email?

your welcome , [email protected]