Multiwfn forum

amichalchuk

Member

Registered: 2023-10-24

Posts: 1

Integrating

Hello, we are trying to get to grips with multiwfn and hoping the commmunity can help.
In 4.200.14 of the manual it shows that one can generate effectively NCI surfaces and selectively integrate the charge density only wihtin these basins. We have managed to integrate the charge density within these regions successfully.

In section 3.200.14 it however suggests that any multiwfn-supported function can be integrated, and we would like to integrate the laplacian of rho(r) within these basins. We cannot however quite figure out how to do this (and even if it would be supported).

Would anybody be able to provide some guidance on this?

Many thanks,
Adam

sobereva

Tian Lu (Multiwfn developer)

From: Beijing

Registered: 2017-09-11

Posts: 1,830

Website

Re: Integrating

Dear Adam

Please note that domain is different from basin. The function illustrated in Section 4.200.14 of Multiwfn manual is used to integrate a function in a domain. Domain is the space enclosed by an isosurface, while basin is the region enclosed by zero-flux surfaces.

In that function, you can use option "2 Select real space function to be calculated for option 1" to choose the real space function used to define domains. Once the domains have been generated, then you can use option "1 Perform integration for a domain" in the post-process menu to choose a function and integrate it within a selected domain.

However, note that this function performs integration based on evenly distributed grids, if the real space function to be integrated varies sharply in the selected domain, then the integration accuracy will be limited (depending on the grid spacing).

Best,

Tian