Effect of isotope on state-to-state dynamics for reactive collision reactions O(3P)+H2+→OH++H and O(3P)+H2+→OH+H+ in ground state 12A″ and first excited 12A′ potential energy surfaces*

Abstract

We carry out quantum scattering dynamics and quasi-classical trajectory (QCT) calculations for the O + H 2 + reactive collision in the ground (12A″) and first excited (12A′) potential energy surface. We calculate the reaction probabilities of O + H 2 + ( v = 0 , j = 0 ) → OH + + H and O + H 2 + ( v = 0 , j = 0 ) → OH + H + reaction for total angular momentum J = 0. The results calculated by QCT are consistent with those from quantum mechanical wave packet. Using the QCT method, we generate in the center-of-mass frame the product state-resolved integral cross-sections (ICSs); two commonly used generalized polarization-dependent differential cross-sections (PDDCSs), (2π/σ)(dσ 00/dω t), (2π/σ)(dσ 20/dω t); and three angular distributions of the product rotational vectors, P(θ r), P(ϕ r), and P(θ r, ϕ r). We discuss the influence on the scalar and vector properties of the potential energy surface, the collision energy, and the isotope mass. Since there are deep potential wells in these two potential energy surfaces, their kinetic characteristics are similar to each other and the isotopic effect is not obvious. However, the well depths and configurations of the two potential energy surfaces are different, so the effects of isotopic substitution on the integral cross-section and the rotational polarization of product are different.