CHARGE-TRANSFER OF N-4+ WITH ATOMIC-HYDROGEN

State-dependent cross sections and rate coefficients for the charge-transfer process N4++H --> N3+(2s3l) + H+ for l = s,p,d in the collision-energy range from 0. 1 eV to 8 keV are presented. A close-coupled quantum-mechanical method is employed, and it is argued that the molecular-state expansion method without translation factors is a valid low-energy approximation for charge-transfer processes. We show that the method does not suffer from the electron-origin problem. The spin-coupled valence-bond method is used to construct both ab initio potential curves and adiabatic coupling elements. The calculated cross sections exhibit variations with energy, which we propose are a manifestation of Stueckelberg oscillations. The cross sections are compared with measured total cross sections for electron capture by N4+ ions in collisions with hydrogen. Agreement is excellent in the collision-energy range from 4.1 to 182 eV/amu.