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sayan307

Member

Registered: 2019-01-14

Posts: 38

Re: TrEsp Charges using ORCA

Hi Tian,

I deleted the previous post because of confusion. So, basically, when density=transition=state of interest is given in the input, the dipole moment printed at the end of Gaussian output is wrong which needs to be divided by sqrt(2). This is true for any DFT functional.

However, If I do a normal TD-DFT without "density=transition=state of interest " statement, then what dipole moment is printed at the end of output...? is it the transition dipole moment for the first excited state (as in Gaussian the default is the first excited state) or is it the ground state dipole moment...? I am dealing with B3LYP, CAM-B3LYP and wB97X functional and I noticed that for wB97X, TDM printed at the end is exactly equal to my first excited state TDM, whereas for B3LYP/CAM-B3LYP those values are different.

So, I want to know what is that dipole moment printed at the end of Gaussian output, when you do a normal TD-DFT calculation...? and whether it's value is correct or not..? Hope you have understood my confusion. Thanks.

Best,
Sayan

Last edited by sayan307 (2019-02-05 17:56:48)

sobereva

Tian Lu (Multiwfn developer)

From: Beijing

Registered: 2017-09-11

Posts: 1,468

Website

Re: TrEsp Charges using ORCA

Dear Sayan,

Several examples:

# B3LYP/6-31G* TD: Dipole moment of ground state at B3LYP/6-31G* level, it is equivalent to "# B3LYP/6-31G*"

# B3LYP/6-31G* TD(root=x) density: Dipole moment of the xth excited state at TD-B3LYP/6-31G* level based on relaxed density

# B3LYP/6-31G* TD(root=x) density=rhoci: Dipole moment of the xth excited state at TD-B3LYP/6-31G* level based on unrelaxed density

# B3LYP/6-31G* TD(root=x) out=wfn: If you are using relatively new revision of G09, or G16, the printed dipole moment is the same as "# B3LYP/6-31G* TD(root=x) density", because "out=wfn" implies "density" keyword. While if you are using much order version, the printed dipole moment is the same as "# B3LYP/6-31G*".

Above rules hold for all kinds of DFT functionals except for the double-hybrid ones.

Best,

Tian

sayan307

Member

Registered: 2019-01-14

Posts: 38

Re: TrEsp Charges using ORCA

Hi Tian,

The first point holds correct. This means when I used # B3LYP/6-31G* TD, the dipole moment printed at the end is the ground state dipole moment.

However, when I used # B3LYP/6-31G* TD(root=x) density or # B3LYP/6-31G* TD(root=x) density=rhoci, the dipole moment printed at the end is not the same in the earlier transition electric dipole moment column for the state x. If I can understand your previous reply correctly, then both these dipole moments before  L06 module and at the end should be same for # B3LYP/6-31G* TD(root=x) density or # B3LYP/6-31G* TD(root=x) density=rhoci inputs... right...? but for my calculations these are different. I am using the new revision of G09.

Thanks,
Sayan

sobereva

Tian Lu (Multiwfn developer)

From: Beijing

Registered: 2017-09-11

Posts: 1,468

Website

Re: TrEsp Charges using ORCA

Hi Tian,

The first point holds correct. This means when I used # B3LYP/6-31G* TD, the dipole moment printed at the end is the ground state dipole moment.

However, when I used # B3LYP/6-31G* TD(root=x) density or # B3LYP/6-31G* TD(root=x) density=rhoci, the dipole moment printed at the end is not the same in the earlier transition electric dipole moment column for the state x. If I can understand your previous reply correctly, then both these dipole moments before  L06 module and at the end should be same for # B3LYP/6-31G* TD(root=x) density or # B3LYP/6-31G* TD(root=x) density=rhoci inputs... right...? but for my calculations these are different. I am using the new revision of G09.

Thanks,
Sayan

Dear Sayan,

Please note that "dipole moment of an excited state", namely <i|-r|i>, is very different "transition dipole moment between ground state and excited state", namely <0|-r|i>.
The "# B3LYP/6-31G* TD(root=x) density" keywords print dipole moment of your selected state at the end of output file, while the data printed prior to L601 is transition dipole moment between ground state and each calculated excited state.

Best,

Tian