Nonadiabatic representation for the i 3Πg- -j 3Δg- complex of H2 and D2

The full ab initio nonadiabatic approach was successfully applied to calculate energy, radiative, and magnetic properties of strong L-uncoupling i 3Πg- and j 3 Δg- states of molecular hydrogen isotopes, for the first time, to our knowledge. The concomitant electronic L-uncoupling matrix elements between the i 3Πg- and j 3 Δg- as well as the i 3Πg-b 3Σu+ , i 3Πg-e 3Σu+ , i 3Πg-c3Πu, and j 3Δgt-c 3Πu transition dipole moment functions were revised by using an electronic full configuration-interaction calculation together with highly accurate ab initio adiabatic potentials taken from the literature. The ab initio results were borne out by quantum-defect theory estimates. Nonadiabatic rovibronic eigenvalues and eigenfunctions for the bound i 3Πg--j 3 Δg- perturbation complex were derived by direct numerical solutions of the two channel-coupling radial equations. The theoretical term values of the complex for H2 and D2 agree with their experimental counterparts within 0.5-1.5 cm-1. For the overwhelming majority of levels, the calculated magnetic g factors coincide with the measured ones within their experimental accuracy. The predicted rovibronic transition probabilities to the lower-lying b 3Σu+ , c 3Πu , and e 3Σu+ states completely resolve perplexing problems of the radiative data in experiments: lifetimes, branching ratios of fluorescence decay to the b 3Σu+ and c 3Πu+ states, and the intensity distribution in rotational structure of the i 3Πg--j 3Δg--> c 3Πu± transitions.