Multiwfn forum

anupthms000

Member

Registered: 2020-05-23

Posts: 3

Calculate ?r and Λ indices to characterize various electron excitation

Dear Sr
   I am trying to calculate ?r and Λ indices to characterize various electron excitation of Donor-Acceptor-Donor type dyes.  The ?r values obtained is less than 1 A. Can I be definite that my molecule is having LE type excitation than charge transfer type. Or these data is only valid for Donor- Acceptor dyes or is it valid of symmetric D-A-D type dyes.

sobereva

Tian Lu (Multiwfn developer)

From: Beijing

Registered: 2017-09-11

Posts: 1,468

Website

Re: Calculate ?r and Λ indices to characterize various electron excitation

Using ?r to judge type of excitation for D-A-D type of system may be misleading. If the CT character is strong but the CT direction is symmetric with respect to A, the ?r may still be very small.

I highly encourage you to use hole-electron analysis module (see Section 4.18.1 of Multiwfn manual for example) to visualize distribution of hole and electron, only when the CT is found to be unidirectional, the ?r can be used to discuss CT character.