High resolution vacuum ultraviolet emission spectrum of D2 from 78 to 103 nm: The D 1Piu-->X 1Sigmag+ and D' 1Piu--->X 1Sigmag+ band systems

International audienceThe emission spectrum of the D2 molecule has been studied at high resolution in the vacuum ultraviolet region 78.5-102.7 nm. A detailed analysis of the two D 1Piu-->X 1Sigmag+ and D' 1Piu--->X 1Sigmag+ electronic band systems is reported. New and improved values of the level energies of the two upper states have been derived with the help of the program IDEN [V. I. Azarov, Phys. Scr. 44, 528 (1991); 48, 656 (1993)], originally developed for atomic spectral analysis. A detailed comparison is made between the observed energy levels and solutions of coupled equations using the newest ab initio potentials by Wolniewicz and co-workers [J. Chem. Phys. 103, 1792 (1995); 99, 1851 (1993); J. Mol. Spectros. 212, 208 (2002); 220, 45 (2003)] taking into account the nonadiabatic coupling terms for the D 1Piu state with the lowest electronic states B 1Sigmau+, C 1Piu, and B' 1Sigmau+. A satisfactory agreement has been found for most of the level energies belonging to the D and D' states. The remaining differences between observation and theory are probably due to nonadiabatic couplings with other higher electronic states which were neglected in the calculations