Enhancement of the molecular electron chirality by electronic excitation

TL;DR

This paper demonstrates that electronic excitation enhances molecular electron chirality (MEC) in H₂Te₂ and H₂Se₂, with the enhancement explained by contributions from the highest occupied molecular orbital and orbital mixing effects.

Contribution

It confirms that electronic excitation increases MEC and provides a detailed explanation involving molecular orbital contributions and atomic orbital mixing effects.

Findings

Electronic excitation enhances MEC in H₂Te₂ and H₂Se₂.

The MEC enhancement is explained by the highest occupied molecular orbital contributions.

Orbital mixing between different atoms significantly influences MEC.

Abstract

Previously, it was predicted that the parity-violating energy difference (PVED) between enantiomers and the molecular electron chirality (MEC), which is the integrated value of the electron chirality density over the entire molecule are enhanced for ionization or electronic excitation. Following the confirmation of the enhancement of the PVED by electronic excitation in our previous papers, the present work confirms that electronic excitation enhances the MEC for H$_2$Te$_2$ and H$_2$Se$_2$. The PVED in the first excited state is explained by the contribution from the highest occupied molecular orbital if the PVED contribution from the highest occupied molecular orbital in the ground state dominates over any other contributions. In this paper, it is checked whether this explanation can also be applicable to the MEC. It is also reported that the MEC is not the simple sum of contributions from each atom and the mixing by the superposition between atomic orbitals of different atoms is important.