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Hengyuan

Member

Registered: 2025-09-17

Posts: 9

Integrating grid data in cube in whole space

Dear Tian,

I tried to calculate the overlap between HOMO density and LUMO density from an orca gbw file, and I am using Multiwfn version 3.8, update date 2026-Jan-7. I saved the orbital probability densities in cube files, and multiplied them together through the multiplication in Grid data calculation. However, I couldn't find the integration option for grid data, could you please elaborate on this? Thank you.

Best,
Hengyuan

Hengyuan

Member

Registered: 2025-09-17

Posts: 9

Re: Integrating grid data in cube in whole space

I found the exact functionality I wanted in the manual 3.100.11 Calculate overlap and centroid distance between two orbitals. However, does the orbital index start with 0 or 1? As 0,0 is the exit code, I would assume the orbital index start with 1?

sobereva

Tian Lu (Multiwfn developer)

From: Athens, Greece

Registered: 2017-09-11

Posts: 2,265

Website

Re: Integrating grid data in cube in whole space

Hello,

In Multiwfn, all indices, including orbital indices, always starts from 1 (PS: I quite dislike starting from 0)