Multiwfn forum

shaun

Member

Registered: 2023-11-12

Posts: 7

HOMO distribution vs Charge distribution for explaining quenching rate

Dear Multiwfn Community,

I am Suhyun Park, a graduate student studying Exciplex in Korea.

I tried to explain the change in PET (Photoinduced Electron Transfer) quenching rate due to the change in donor through calculation.

At first, I tried to explain it with the charge distribution of donors, but I thought it was not appropriate because the electrons that actually participate in PET are the electrons in the HOMO of the donor in the GS state. So I want to check how widely the charge distribution of the HOMO is distributed in the direction of the acceptor approaching.

Can anyone recommend an appropriate MULTIWFN function to make these calculations?

Thank you,

Sincerely,
Suhyun Park

Last edited by shaun (2023-11-17 08:58:12)

shaun

Member

Registered: 2023-11-12

Posts: 7

Re: HOMO distribution vs Charge distribution for explaining quenching rate

Maybe I could rephrase the question a bit and use multwfn to draw contour plots for a specific plane in a specific MO(i.e. HOMO) and export the raw data for that?

sobereva

Tian Lu (Multiwfn developer)

From: Beijing

Registered: 2017-09-11

Posts: 1,768

Website

Re: HOMO distribution vs Charge distribution for explaining quenching rate

You can use main function 4 to draw plane map (color-filled contour map is recommended) of HOMO in a suitable plane, see Section 4.4 of Multiwfn manual for example of various kinds of plane map.

shaun

Member

Registered: 2023-11-12

Posts: 7

Re: HOMO distribution vs Charge distribution for explaining quenching rate

Thank you so much for your kind reply!

I think 4-4(value of orbital wave function) then picking HOMO seems appropriate for it. but it could be just not electron density of HOMO but 'value' of HOMO. If I wanted to see the distribution of electrons occupying a particular orbital (i.e. HOMO), could I just square the value I got directly above it to get 'HOMO distribution'(which wouldn't actually be the electron distribution, but would still be proportional to the value I squared)?

Thank you as always for your kindness and knowledge and for this software you have created!

sobereva

Tian Lu (Multiwfn developer)

From: Beijing

Registered: 2017-09-11

Posts: 1,768

Website

Re: HOMO distribution vs Charge distribution for explaining quenching rate

You can.
For example, you just want to plot density of orbital 8, after loading the input file, you should input
6 //Modify wavefunction
26 // Set occupation of some orbitals
0 //Select all orbitals
0 //Set occupancy to zero
8 //Choose orbital 8
1 //Set its occupancy to 1
q //Return
-1 //Return to main menu

After that, if you plot electron density in main function 4, then it will correspond to probability density of orbital 8, because currently only orbital 8 with single electron contributes to the electron density.

shaun

Member

Registered: 2023-11-12

Posts: 7

Re: HOMO distribution vs Charge distribution for explaining quenching rate

Thank you so much! I admire your depth of knowledge and kindness.

This software seems to be really useful, I'll be sure to cite it with good results, thanks!