Dear all, 

Now i have the way to model TDM direction.

Thanks. 

I am interested ini know how do you determine the orientation of the TDM?

wHEN i DID SOME MEASUREMENTS OF THE FLUORESCENCE ANYSOTROPY OF D 2h MOLECULES, LIKE PERYLENE AND tERRYLENE , I HAD TO DEFINE THE TDM FROM SYMMETRY OPERATIONS ... AND IT WAS VEEERY TIME CONSUMING TO DO BY HAND ALL THE MINIMUM REPRESENTATION AND SO ON ...

How is your method ? 

Pedro

I am surprised because we did those calculations almost 50 years ago for the more complicated Triplet-Triplet (T1-Tx) transitions in symmetric PAH's like pyrene

Hey Harry

Actually you are right. I have seen some of those papers, with prof Schmidt and Van der Waal about naphthalene examples. But for these cases , I am affraid that is just a qualitative determination of the dipole orientation based on symmetry operators

He wants to know wheter he can get the quantitative value of the transition dipole moment by using this data. Is it true Nikhil?

Nikhil has the permanent dipole moment for the ground state optimized geometry and for the excited state optimized geometry from DFT calculations.

regards both

=)

Pedro

good that you urge the original questioner what he actually wants.

He now mentions he needs the the direction of the transition moment

Dear Harry,

It is very clearly mentioned in question itself that i needed the direction of TDM (not its magnitude) and in my previous reply i mentioned that now i have a way to find TDM direction.

Dear Pedro, 

Sorry for extremely late reply.

I have computed TDM direction as well as it magnitude for different electronic excitation. Please have a look at above mentioned web-links and in case of any difficulty please email me at [email protected]

http://scholar.google.co.in/scholar_url?hl=en&q=http://www.researchgate.net/publication/51871563_Multiwfn_a_multifunctional_wavefunction_analyzer/file/50463527f4ca058be7.pdf&sa=X&scisig=AAGBfm2J2ahJmeryjW-gausiWEPo6lplzQ&oi=scholarr&ei=lvPwU_rcBYqWuASEtoLIDA&ved=0CBwQgAMoADAA

http://multiwfn.codeplex.com/     

Article Multiwfn: A multifunctional wavefunction analyzer

How to calculate the magnitude of transition dipole moment?

Hello, use this:

Case of Water(H2O), you can use organic molecules but the methods remains the same in Gaussian09.

Input look like this:

# b3lyp/6-31g freq freq iop(7/33=1)

Output look like this:

Dipole derivative wrt mode 1: -1.29096D-14 -2.16863D+02 -1.22125D-14 Dipole derivative wrt mode 2: 9.34335D-16 0.00000D+00 -3.68709D+00 Dipole derivative wrt mode 3: -4.22412D-15 -1.06581D-13 -1.26465D+01

etc

Hope This Helps,

Regards

Ajay khanna