Multiwfn forum

Aerael

Member

From: Germany, Bavaria, Munich

Registered: 2020-10-08

Posts: 16

Integrate orbital density in external basins

Dear Tian Lu & MutliwWFN folks,

is there a way to find out how much each orbital contributes to the occupation of a QTAIM basin?

I have tried to get those numbers myself, but failed:

By loading a wave function, doing a basin analysis for the whole electronic density, I obtain the QTAIM basins.
If I now go ahead and delete all orbitals but the one of interest, the options for basin analysis vanish and I cannot integrate my (by now one-orbital) electron density in these basins anymore.
My next try was loading a modified wave function file containing only the orbital of interest, trying to load the basin cube on top of it, and then to integrate this one-orbital density within the ell-electron basins -- But I do not find the option to do so.

Thanks so much as always for your great help, it is most appreciated!
Daniel

Last edited by Aerael (2022-06-10 13:27:30)

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Daniel, PhD student at LMU Munich, Germany under Prof. Dr. Klüfers. Special interest: transition metal nitrosyl complexes.

sobereva

Tian Lu (Multiwfn developer)

From: Beijing

Registered: 2017-09-11

Posts: 1,768

Website

Re: Integrate orbital density in external basins

Dear Daniel,

Please perform AIM basin analysis as usual (see example in Section 4.17.1 of manual) first. After generation of the basins, you can find an option "11 Calculate orbital compositions contributed by various basins" (if you don't see it, that means your version is too old). By using it you can obtain contribution of every AIM basin to specific orbitals. Assume that basin 4 contribute to MO 10 by 34%, and MO 10 is a doubly occupied orbital, then MO 10 contribute to population of basin 4 by 0.34*2=0.68; in other words, 0.68 of 2.0 electrons in MO 10 belongs to basin 4.

Best,

Tian

Aerael

Member

From: Germany, Bavaria, Munich

Registered: 2020-10-08

Posts: 16

Re: Integrate orbital density in external basins

Dear Tian,

thanks so much, this works, but needs improvement.

Would it be possible to include a simple switch option to ONLY integrate for occupied MOs, instead of over the whole set?
(Or, alternatively, to be able to specify a set like 2,4-8,11-19 like for other functionalities?)
It is very tedious to do all MOs by hand, and the whole virtual set is probably never needed.

That would be awesome to have!

Thanks so much and all the best!
Daniel

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Daniel, PhD student at LMU Munich, Germany under Prof. Dr. Klüfers. Special interest: transition metal nitrosyl complexes.

sobereva

Tian Lu (Multiwfn developer)

From: Beijing

Registered: 2017-09-11

Posts: 1,768

Website

Re: Integrate orbital density in external basins

Dear Daniel,

In the aforementioned function you can see an option "-4: Export composition of every basin in every orbital to orbcomp.txt", after exporting the orbcomp.txt, you can easily use such as "grep" command in Linux to extract composition of an basin in all orbitals.

Best regards,

Tian

Aerael

Member

From: Germany, Bavaria, Munich

Registered: 2020-10-08

Posts: 16

Re: Integrate orbital density in external basins

Thank you Tian,

Yes, I am aware of that. I AM currently exporting all MOs at once with the -4 option, as you suggest.

The thing is, integrating 1000 MOs takes a lot more time than integrating 50 MOs, and I am (currently) mainly interested in the occupied ones, which leaves me with 95% junk (waste of computation time and ressources).
I was just trying to save some energy, and at the same time not do 50 MOs separately by hand.

It's not an urgent request, I just thought it might be a small and quick upgrade to a very useful utility. ^^

Thanks so much as always!
Daniel

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Daniel, PhD student at LMU Munich, Germany under Prof. Dr. Klüfers. Special interest: transition metal nitrosyl complexes.

sobereva

Tian Lu (Multiwfn developer)

From: Beijing

Registered: 2017-09-11

Posts: 1,768

Website

Re: Integrate orbital density in external basins

Dear Daniel,

In fact, there is no significant difference in cost of calculating compositions of 50 and 1000 MOs, because the most time-consuming intermediate data is shared by all orbitals.

You can extract needed data only by using one command. For example, extracting contribution of basin 5 to all orbitals, you can input

grep " 5 " orbcomp.txt |nl

The result is

1 5 0.000 % 2 5 0.000 % 3 5 0.000 % 4 5 99.998 % 5 5 1.094 % 6 5 0.324 % 7 5 54.351 % 8 5 3.155 % 9 5 27.365 % 10 5 26.118 % 11 5 22.939 % 12 5 18.619 % 13 5 20.657 % 14 5 15.225 % 15 5 0.260 % 16 5 8.655 %

So, contribution of basin 5 to e.g. MO 14 is 15.225%.

Best regards,

Tian

Aerael

Member

From: Germany, Bavaria, Munich

Registered: 2020-10-08

Posts: 16

Re: Integrate orbital density in external basins

Oooh, of course, because you integrate Gauss functions which are part of all MOs. Sorry, my bad.
Thanks a lot, I will just bite the bullet of long calculations then.

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Daniel, PhD student at LMU Munich, Germany under Prof. Dr. Klüfers. Special interest: transition metal nitrosyl complexes.