Energy dependence of the intramultiplet mixing cross section in Hg–N2 collisions: Conical intersection mechanism, indication at tunneling and interference

Abstract

Experimental results on the energy dependence of the cross section for the intramultiplet transitions in Hg atom induced by collisions with the rotationally cold nitrogen molecules, 3P1,v=0→3P0,v=1, v being the vibrational quantum number of N2 (M. Okunishi, J. Hashimoto, H. Chiba, K. Ohmori, K. Ueda and Y. Sato, J. Phys. Chem. A, 1999, 103, 1742.) are interpreted within rotationally sudden versions of the Landau–Zener and generalized Landau–Zener–Teller models. The broad threshold region of the cross section is ascribed to noticeable dependence of the avoided crossing seam energy on the collision angle between two conical intersection points (linear and T-shaped configurations) and to the tunneling/interference effects in the transition probability. The experimental energy dependence of the cross section is consistent with the anticipated values of the crossing-point energy at the optimal configuration.