Quantal treatment of the low energy collision of Ne*(3P0,2) with H2(1∑+g,v=0)

Abstract

A close‐coupling channel computation of Ne*(³P_0,2)–H₂ (¹∑⁺_g, v=0) collisions, using the ab initio potentials given in a preceding paper, is reported. The molecule is considered as a rigid rotator. The autoionizing character of states dissociating into Ne* (2p⁵3s)+H₂ is ignored. Consequently Penning and chemi‐ionizations are not considered. Combined fine structure and rotational transitions are the only inelastic channels expected. By means of a deflation procedure, collision channels leading to Ne*(¹P₁) are shown to be negligible in the present energy range (E≤175 meV). The ‘‘fragment’’ basis (i.e., Ne*+H₂ at infinite R) is adapted to the collision treatment since all off‐diagonal elements of the electronic Hamiltonian, including the spin–orbit interaction (static couplings) are small. The coupling of angular momenta ( j₁=0,1,2 of Ne*, j₂=0,2 of para‐H₂, 1 of ortho‐H₂, l for the relative motion) leads to 27 coupled equations for ortho‐H₂ and 54 equations for para‐H₂, for each value of the total angular momentum J. These equations are solved by using the algorithm of Gordon, and the 81×81 S matrix is derived. The rotational excitation ( j₂=0→2) probability takes a maximum value of the order of 10⁻² at J≊15.