Finite temperature quantum statistics of H$_3^+$ molecular ion

TL;DR

This study uses path integral Monte Carlo simulations to analyze the quantum statistical behavior of the H₃⁺ molecular ion across various temperatures, emphasizing the importance of quantum effects in its structure and dissociation.

Contribution

It provides the first detailed quantum statistical analysis of H₃⁺, highlighting the significance of quantum nuclear effects on its dissociation temperature and structure.

Findings

Dissociation temperature around 4000 K.

Quantum effects significantly influence proton dynamics.

Quantum and classical simulations show notable differences.

Abstract

Full quantum statistical $NVT$ simulation of the five-particle system H$_3^+$ has been carried out using the path integral Monte Carlo method. Structure and energetics is evaluated as a function of temperature up to the thermal dissociation limit. The weakly density dependent dissociation temperature is found to be around $4000$ K. Contributions from the quantum dynamics and thermal motion are sorted out by comparing differences between simulations with quantum and classical nuclei. The essential role of the quantum description of the protons is established.