Quantum calculations of H2-H2 collisions: from ultracold to thermal energies

TL;DR

This paper presents comprehensive quantum scattering calculations for H2-H2 collisions across a wide energy range, providing detailed cross sections and rate coefficients validated against experimental data.

Contribution

It introduces full-dimensional quantum calculations of H2-H2 collisions from ultracold to thermal energies using an accurate potential energy surface, without decoupling approximations.

Findings

Good agreement with experimental cross sections and rate coefficients.

Detailed data across a broad energy range from 1 mK to 1 eV.

Validation of the quantum scattering approach for molecular collisions.

Abstract

We present quantum dynamics of collisions between two para-H2 molecules from low (1 mK) to high collision energies (1 eV). The calculations are carried out using a quantum scattering code that solves the time-independent Schrodinger equation in its full dimensionality without any decoupling approximations. The six-dimensional potential energy surface for the H4 system developed by Boothroyd et al. [J. Chem. Phys. 116, 666 (2002)] is used in the calculations. Elastic, inelastic and state-to-state cross sections as well as rate coefficients from T = 1 K to 400 K obtained from our calculations are compared with available experimental and theoretical results. Overall, good agreement is obtained with previous studies.