Fully State-Resolved Differential Cross Sections for the Inelastic Scattering of the Open-Shell NO Molecule by Ar

Abstract

State-resolved differential cross sections (DCSs) for the inelastic scattering of NO( j " = 0.5, Ω" = 1/2) + Ar → NO( j ′, Ω′ = 1/2, 3/2) + Ar were obtained at a collision energy of 516 cm ⁻¹ , both experimentally and theoretically. A crossed molecular beam ion-imaging apparatus was used to measure DCSs for 20 final ( j ′, Ω′) states, including spin-orbit conserving (ΔΩ = 0) and changing (ΔΩ = 1) transitions. Quantum close-coupling scattering calculations on ab initio coupled-cluster CCSD(T) and CEPA (correlated electron pair approximation) potential energy surfaces were also performed. Although small discrepancies were found for the ΔΩ = 1 transitions, we find marked agreement between theory and experiment for the collision dynamics of this system, which is the paradigm for the collisional relaxation of a molecular radical.