On the Inconsistency of Spectroscopic Data on the (3dπ)i~(3)II_(g)~(-) and (3dδ)j~(3)Δ_(g)~(-) States of the Hydrogen Molecule and the Problems of Semiempirical and Ab Initio Calculations

摘要

Quantitative analysis of the entire set of available experimental, ab initio, and semiempirical data on the electronic-vibrational-rotational (EVR) terms, the probabilities of radiative EVR transitions, and the lifetimes of EVR levels of the i~(3)II_(g)~(-) and j~(3)Δ_(g)~(-) states of the hydrogen molecule is performed for the first time on the basis of well-known statistical criteria. It is ascertained that, presently, there are significant contradictions between (1) the experimental data obtained by different methods and different researchers, (2) the results of different calculations, and (3) the results of different ab initio calculations and experimental data. It is shown that the inference made by Adamson et al. (Phys. Rev. A (2000)) about removing the noted contradictions on the basis of ab initio calculations (performed by Adamson et al.) and the experiment of Ray and Lafyatis (Phys. Rev. Lett. (1996)) is unjustified. Moreover, the new data have only aggravated the situation. Actually, in order to eliminate the contradictions revealed in this study (as well as those noted previously), it is necessary to (1) obtain experimental data on the relative probabilities of spontaneous transitions to different low-lying unstable electronic states (b~(3)Σ_(u)~(+) and c~(3)II_(u)~(+)) and the lifetimes of EVR levels of the i~(3)II_(g)~(-) and j~(3)Δ_(g)~(-) states for wide ranges of the values of the vibrational and rotational quantum numbers (the available data are too fragmentary to make categorical statements); (2) carry out independent ab initio calculations of these values; and (3) use quantitative statistical methods both to compare data obtained in different experiments and to find out how well different theoretical models can describe experimental data.