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Arivu

Member

Registered: 2025-12-27

Posts: 12

NTOs Vs Hole-Electron Analysis in ORCA

Dear Prof. Tian,
    I would like to generate NTOs for S1, T1, T2, etc. Few doubts are arising.
1. NTOs are usually pairs of orbitals that shows hole - electron movement during excitation. Many papers reporting only one pair for S1 (with both signs on orbital), T1 (with both signs on orbital), T2 (with both signs on orbital), etc., how is it possible?
2. Hole-Electron analysis overcomes this problem of looking at each pair. But if I export hole.cub and electron.cub separately and loading into VESTA does not give the combined lobes. A few papers show the combined form of hole-electron density in a single form like NTO of S1, and some papers they like the one mentioned in point number 1. What is the difference and how to generate those plots?

I have used ORCA for calculation as well as for NTOs generation. Using Multiwfn also I could not get those kind of pictures.
Kindly refer to the pictures attached in two different forms.

Thanks and regards
Arivu

Last edited by Arivu (2026-09-16 14:57:59)

sobereva

Tian Lu (Multiwfn developer)

From: Athens, Greece

Registered: 2017-09-11

Posts: 2,284

Website

Re: NTOs Vs Hole-Electron Analysis in ORCA

Hello,

Perhaps due to network issue, currently I cannot view your uploaded pictures, I just reply you according to your text description:

1 If a paper only reports one pair of NTO, usually it means that there is only one NTO transition dominates the electronic excitation, for example, with contribution higher than 90-95%.

2 The hole-electron analysis in Multiwfn is not "looking at each pair", but generates hole and electron distributions, the hole->electron transition representation can always 100% describe any single-electron excitation, so it is particularly important and useful when there is no dominate MO transition or NTO transition.

You can use Multiwfn to generate cube file of hole and cube file of electron, respectively. Then they can be simultaneously shown in VMD (I am sure if it is also possible in VESTA), you just need to load the two cube files into VMD in turn, and then set both their drawing method as "Isosurface" and properly adjust isovalue in the Graphics - Representation interface.

Best regards,

Tian

Arivu

Member

Registered: 2025-12-27

Posts: 12

Re: NTOs Vs Hole-Electron Analysis in ORCA

Dear Prof. Tian,
    Got it. Thank you so much for your reply. 
Regards
Arivu