Finite Nuclear Mass and Relativistic Effects on the Rotational Constant of Molecular Hydrogen

Abstract

Corrections to the rotational constant of molecular hydrogen associated with finite nuclear mass and relativistic effects are calculated. They are significantly smaller in magnitude than are the corresponding corrections previously employed. After these refinements are made, the values 60.8566±0.004, 45.6548±0.003, and 30.4527±0.002 cm−1 are obtained for the Dunham Be values of H2, HD, and D2. The present theoretical results show reasonably good agreement with Stoicheff's measurements on H2, HD, and D2, and with recent measurements on H2 by Fink, Wiggins, and Rank, while showing less good agreement with the measurements of Herzberg and Howe. The present agreement represents decided improvement over the results of previous analysis.