Abstract

The precise experimental determination of the dissociation energy, D₀, for the ground electronic state of the hydrogen molecule has remained as a basic problem for testing present molecular theory. The latest theoretical value of D₀(H₂), including relativistic, radiative, and nonadiabatic corrections, has been calculated¹ to probably better than ±0.1 cm⁻¹. However, experimental evaluations have not yet achieved this level of accuracy. Most recently, McCormack and Eyler² have obtained a value of D₀(H₂) accurate to ±0.2 cm⁻¹, by using high-resolution double-resonance spectroscopy. We report here a determination of D₀(H₂) with an accuracy of ±0.06 cm⁴ obtained by single-photon laser spectroscopy in the extreme ultraviolet region (XUV).

© 1992 Optical Society of America