Multichannel quantum defect theory treatment of triplet gerade and ungerade d-symmetry levelsof H2 and its isotopomers

This work presents a systematic multichannel quantum defect theory (MQDT) analysis of the triplet d-symmetry levels of the hydrogen molecule. First, a new compilation of the best available experimental term values for these levels was prepared. Second, R-dependent quantum defect matrices for the 3Πu, 3Πg, and 3Δg states of H2 were obtained from ab initio potential-energy curves and used in an ab initio MQDT calculation of all known triplet d-symmetry rovibronic levels of H2, HD, and D2. For a few of these levels previous ab initio calculations have been reported. The agreement currently obtained is generally significantly better than that in previous work. Finally, the quantum defect matrices are used to calculate the electronic transition moments 3Πu [Formula: see text] 3Πg, 3Δg as functions of energy and internuclear distance, R, for application in a companion article. PACS Nos: 31.15Ar, 33.20Wr, 34.10+x, 34.80Kw