Multiwfn forum

mbergami

Member

Registered: 2020-01-12

Posts: 10

Overlap between specific orbitals

Hi all,

I need to calculate the overlap between two specific orbitals obtained with UHF calculation for a system compused by 10 water molecules,
one additional electron and one positron. In this calculation, I positioned GTF's for electrons on atom coordinates, and also a extra expansion center on origin (center of cavity). The GTF's positioned on atom coordinates (6-31G+(d,p)) and on origin (aug-cc-pVTZ) are different.

For the positron I positioned just one expansion center on origin with the same GTF (aug-cc-pVTZ) used for extra center of electrons. Therefore, the electronic wave function has different GTF's (6-31G+(d,p) and aug-cc-pVTZ) than positronic wave function (aug-cc-pVTZ). I have separate molden files for beta electrons, alpha electrons and the positron.

My question is:

Is there some problem to create just one .wfn file for alpha electrons and positron, and use this file to calculate overlap between alpha orbital with positron orbital using the function "3.200.10 Output various kind of integral between orbitals"? Is this function use the information of GTF's to calculate the overlap?

Thanks for the attention,

Mateus Bergami

mbergami

Member

Registered: 2020-01-12

Posts: 10

Re: Overlap between specific orbitals

In this case, I modify the molden file of alpha electrons including the positron orbital and output the .wfn for this modified molden file.

sobereva

Tian Lu (Multiwfn developer)

From: Beijing

Registered: 2017-09-11

Posts: 1,776

Website

Re: Overlap between specific orbitals

Dear Mateus Bergami,

I suggest you use subfunction 6 of main function 200, this function is able to directly calculate overlap (or overlap of norm) for orbitals in two different wavefunction files, therefore you do not need to find a way to merge the two wavefunctions files. Please check Section 3.200.6 of Multiwfn manual for introduction of this function.

Best regards,

Tian

mbergami

Member

Registered: 2020-01-12

Posts: 10

Re: Overlap between specific orbitals

Dear Tian,

I am trying to obtain overlap integral of square of the two orbitals from two wavefunctions files. I just know to calculate this overlap integral using function 3.100.11, in this case I can't use two wavefunctions files with this function.

In this case, is there some way to calculate the overlap integral of square of the two orbitals without to merge the two wavefunctions files?

Thanks for the attention,

Mateus Bergami

sobereva

Tian Lu (Multiwfn developer)

From: Beijing

Registered: 2017-09-11

Posts: 1,776

Website

Re: Overlap between specific orbitals

I have updated Multiwfn 3.7(dev) today, now in the subfunction 6 of main function 200, you can select option -3 to export Snorm2mat.txt in current folder, which contains overlap integrals between square of orbitals among two specific wavefunction files.

mbergami

Member

Registered: 2020-01-12

Posts: 10

Re: Overlap between specific orbitals

Hi Tian, thanks for your help as usual!

I used the subfunction 6 of main function 200 and the result for overlap integrals between square of orbitals are too high, for my system the overlap is 0.91 and the overlap of square is 0.93. I think there is something wrong...

I did other test with two .wfn files of alpha and beta orbitals respectively, and the overlap of square calculated with subfunction 6 of main function 200 is different than the result obtained with the subfunction 11 of main function 100 using just one file with alpha and beta electrons.

Last edited by mbergami (2020-05-29 21:54:51)

sobereva

Tian Lu (Multiwfn developer)

From: Beijing

Registered: 2017-09-11

Posts: 1,776

Website

Re: Overlap between specific orbitals

There is a bug, sorry. I just updated the 3.7(dev) on Multiwfn website, now the result is correct.