Leading-order QED effects in the ground electronic state of molecular hydrogen

TL;DR

This paper presents highly precise calculations of the leading-order QED correction to the ground state of molecular hydrogen, improving accuracy and resolving previous uncertainties, yet still showing some discrepancies with experimental data.

Contribution

The study provides the most accurate QED correction calculations for molecular hydrogen to date, reducing numerical uncertainties and addressing prior computational limitations.

Findings

Numerical results achieved with about 10^{-8} precision

Major uncertainties in previous results have been eliminated

Persistent discrepancy with experimental measurements in HD at 1.9 sigma

Abstract

We perform highly accurate calculations of the leading order QED correction to the ground electronic state of molecular hydrogen. Numerical results are obtained for a grid of the internuclear distances $R=0-10$ au with the relative precision of about $10^{-8}$. The major numerical uncertainty of previous QED results [K. Piszczatowski et al., JCTC $\textbf{5}$, 3039 (2009)] has been eliminated. Nevertheless, the discrepancy with measurements in HD at the level of 1.9 $\sigma$ persists.