Rovibrational computations for He$_2^+$ X $\Sigma_\mathrm{u}^+$ including non-adiabatic, relativistic and QED corrections

TL;DR

This paper provides highly accurate rovibrational energy calculations for the helium dimer cation, including various quantum corrections, improving upon previous work with broader range and better error control.

Contribution

The study introduces an improved computational approach for the helium dimer cation's potential energy and quantum corrections, achieving higher accuracy and broader configuration coverage.

Findings

All rovibrational bound states reported with 0.005 cm$^{-1}$ accuracy.

Comprehensive inclusion of non-adiabatic, relativistic, and QED corrections.

Enhanced computational methods over previous studies.

Abstract

We report the potential energy curve, the diagonal Born-Oppenheimer, non-adiabatic mass, relativistic, and leading-order QED corrections for the ground electronic state of the helium dimer cation; the higher-order QED and finite-nuclear size effects are also estimated. The computations are carried out with an improved error control and over a much broader configuration range compared to earlier work [D. Ferenc, V. I. Korobov, and E. M\'atyus, Phys. Rev. Lett. 125, 213001 (2020)]. As a result, all rovibrational bound states are reported with an estimated accuracy of 0.005 cm$^{-1}$.