Dissociative attachment of electrons to vibrationally excitedH2

Calculations are reported of the dissociative attachment of low-energy (less than 5 eV) electrons to molecular hydrogen in the states v=0–9 and J=0. The dynamics are treated using resonant scattering theory, fully including the nonlocal and energy-dependent shift and width operators. The necessary coupling terms are taken from the ab initio calculations of fixed-R electron-${\mathrm{H}}_2$ scattering performed by Mündel, Berman, and Domcke [Phys. Rev. A 32, 181 (1985)]. Good agreement with the available experimental data of Schulz and Asundi [Phys. Rev. 158, 2 (1967)] and of Allan and Wong [Phys. Rev. Lett. 41, 1791 (1978)] is achieved. Exploratory calculations were performed to investigate various local approximations to the nonlocal shift operator. The results suggest that the optimum local approximation will, in general, differ from the curve obtained in a fixed-nuclei structure calculation.