Multiwfn forum

ffuser

Member

Registered: 2020-10-20

Posts: 9

Bond order analysis for excited state

Hello.

Is there any “good way” for bond order analysis (BOA) of excited states?
Let me elaborate on the current situation below.

I’m interested in how bond orders change in the excited state from the ground state.
(I’ve tried excited state analysis such as q_CT and density difference already, and now want deeper insight into bonds.)

The problem is that I don’t see many papers related to this subject.
After reading the chapter 3 in the Multiwfn manual,
I recognized that some BOA methods should not be applied to excited state analysis, which requires diffuse functions in basis sets to accurately describe the electron density.
Therefore, in my opinion, fuzzy bond order analysis or laplacian bond order analysis, which don’t heavily depend on basis sets, are good choice.

Is there any comment or any better choice on excited state BOA?
Thanks in advance.

sobereva

Tian Lu (Multiwfn developer)

From: Beijing

Registered: 2017-09-11

Posts: 1,830

Website

Re: Bond order analysis for excited state

Commonly, if your system is not an anion, and the excited state is not a Rydberg state, adding diffuse functions is never needed. Basis set of 3-zeta quality such as def-TZVP or the better one def2-TZVP is sufficient for nicely represent valence excitations of neutral systems. In this case, Mayer bond order can be safely used to examine bonding of excited state, please check Section 4.18.3 of Multiwfn manual for example of excited state bond order analysis.

Of course, the fuzzy bond order and Laplacian bond order you mentioned also work well for excited state and they are fully compatible with diffuse functions.

ffuser

Member

Registered: 2020-10-20

Posts: 9

Re: Bond order analysis for excited state

Thank you for your reply. That’s helpful.