The far-wing excitation and probe technique is applied to observe quasimolecular absorption bands on the blue side of the Hg 6 1S0-6 3P2 atomic line for the Hg-Ar, Hg-Kr, and Hg-Xe mixtures. It is found that the excitation of this band is followed predominantly by a rapid elastic half-collision scattering on the excited state potential yielding the nascent product state Hg(3P2). This gives direct evidence of the assignment of the absorption to the c 31 → X 10 collision induced dipole transition of the Hg-rare-gas quasimolecules. A chance of nonadiabatic transition from the c state is negligibly small compared to the elastic scattering. Analytical procedures are presented to deduce the c-X transition dipole moment from the relevant potential energy curves by making use of the Hund's coupling schemes of the molecular electronic states. The c-X transition dipole moment is estimated as a function of the internuclear distance and is incorporated into the analysis of the observed band profiles. The potential energy curves of the c, A 30+ , and B 31 states are also estimated from the analysis for Hg-Ar and Hg-Kr. The Hg-Xe system shows a small undulation in the c→X band suggesting that it involves a satellite structure due to an extremum of the c-X difference potential.
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