Anharmonicity in rotational and vibrational excitation of H 2 by Li + collisions

Abstract

Integral cross sections for pure rotational and vibrational-rotational excitation of H 2(X 1Σ + g) by Li +( 1S) impact are computed by close-coupling methods at 0.2, 0.6, and 1.2 eV in the c.m. system using vibrational functions that are numerical solutions of the one-dimensional radial Schrödinger equation for harmonic, Morse, and adiabatically corrected Kolos-Wolniewicz (KW) potential functions. Comparison of results employing KW and Morse functions shows excellent agreement for all transitions studied. Findings using harmonic oscillator functions, however, differ noticeably from KW and Morse values for vibrational (0 → 1) and very large rotational (Δ j = 10) transitions, but are satisfactory for lower order (0 → 2, 4, 6, 8) rotational transitions.