Precision tests of nonadiabatic perturbation theory with measurements on the DT molecule

Abstract

First-principles calculations are presented for fundamental vibrational splitting energies of tritium-bearing molecular hydrogen species with the improved treatment of the nonrelativistic, relativistic, and quantum electrodynamic energy contributions resulting in a total uncertainty of 0.00011 cm^{−1} for DT, or about a 100-times improvement over previous results. Precision coherent Raman spectroscopic measurements of Q(J=0–5) transitions in DT were performed at an accuracy of <0.0004 cm^{−1}, representing an even larger 250-fold improvement over previous experiments. Perfect agreement between experiment and theory is found, within 1σ, for all six transitions studied.