# Localized electron wave packet description of chemical bond and excitation: Floating and breathing Gaussian with valence-bond coupling

## TL;DR

This paper introduces a localized electron wave packet model with floating and breathing features, coupled via valence-bond theory, to accurately describe chemical bonds, excitations, and high-harmonic generation in molecules.

## Contribution

It presents a novel wave packet approach with variable position and width, coupled through valence-bond theory, improving the description of molecular electronic states and dynamics.

## Key findings

- Accurately reproduces potential energy curves of LiH in ground states.
- Semi-quantitative excited state energy curves from mean-field quantization.
- Qualitative high-harmonic spectra matching higher-level calculations.

## Abstract

A model of localized electron wave packets (WPs) with variable position and width (floating and breathing) that are spin-coupled as per the valence-bond theory is presented. It produces accurate potential energy curves of LiH in the ground singlet and triplet states. Quantization in a mean-field approximation of the motion of a WP that corresponds to the Li 2s electron generates semi-quantitative potential energy curves of low energy excited states. Real-time semiquantal dynamics of the WP induced by an intense laser pulse gives high-harmonic generation spectra that capture qualitative features of a higher-level wave function calculation.