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### G03 to calculate/estimate the excited dipole moment at DFT

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Author Post
Member
Registered: Apr 2009
Posts: 10
Hi colleagues!
I am very new on this forum and this is my first participation.sorry if put on wrong place.I wana ask:

1-Is it possible in G03 to calculate/estimate the excited dipole moment at DFT
method by applying some finite field like as in ADF?
or some other way..?
2-What is the defaut value of finite field in G03?
regards
shabbir
NENU P.R.China
Member
Registered: Sep 2007
Posts: 20
If you mean the dipole moment in some excited state, I suppose you want to use TDDFT. You should be able to apply fields in X, Y, Z and -X, -Y, -Z directions, and get the dipole moment from the energy difference probably with most electronic structure codes. You can check the manual for the default values.
Member
Registered: Apr 2009
Posts: 10
Thanks for your reply. I have calculated the excited state dipole moment change by using Ee(F)=Ee(0)-detaUF-1/2detaAlpha(F)2 {DOI: 10.1063/1.1415085} and applying two fields of 0.001 in +X and -X because my molecule is planer and charge transfer axis is X so I took this direction.

Now the question arose in my mind is "If molecule lies on two axis(x and y axis) then what should be exect excited state dipolemoment change b/w ground and excited state?

I mean either X or Y-axis or both collectivly. Any comment would be highly appriciating

shabbir@nenu.edu.cn
Member
Registered: Sep 2007
Posts: 20
Since the dipole moment is a vector, you can do vector subtraction in X Y Z separately and then add these to get the total vector. Am I misunderstanding your question?
Member
Registered: Apr 2009
Posts: 10
First of all sorry for being late reply as I was in the middle of these calculations and wanted to discuss after its completion.
Yes I think you are right because in G03 the ground state dipole moment is taken as vector sum of all the three axis. I have all taken the vector sum of these two axis (x,y) while z is about to naught in ground state due to the out of plane of the molecule. Should I also consider this or no need to consider Z-axis as in my cause…?
M.Shabbir
shabbir@nenu.edu.cn

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