Nonadiabatic QED correction to the dissociation energy of the hydrogen molecule

Abstract

The quantum electrodynamic correction to the energy of the hydrogen molecule has been evaluated without expansion in the electron-proton mass ratio. The obtained results significantly improve the accuracy of theoretical predictions reaching the level of 1 MHz for the dissociation energy, in a very good agreement with the parallel measurement [H\"olsch et al., Phys. Rev. Lett. 122, 103002 (2019)]. Molecular hydrogen has thus become a cornerstone of ultraprecise quantum chemistry, which opens perspectives for determination of fundamental physical constants from its spectra.