NONLOCAL EFFECTS IN DISSOCIATIVE ELECTRON-ATTACHMENT TO H-2

Electron scattering by diatomic molecules involving the formation of a single resonance is treated within the configuration-interaction formalism. A technique is presented for solving the resulting nonlocal integro-differential equation for the nuclear motion in the resonant state. This technique is applied to the scattering of electrons by molecular hydrogen (and its isotopes) via the formation of X 2u+ resonance, using a semiempirical model for the resonant state. Numerical cross sections for dissociative attachment, to H2, of electrons with energies below 5 eV are presented and compared both with available experimental data and with those obtained using the local approximation for the complete integro-differential equation. In contrast to the local theory, the nonlocal theory predicts cross sections that exhibit discontinuities at energies at which a new vibrational channel opens up. We also give an upper bound for attachment cross sections that holds for all isotopes of molecular hydrogen for all values of the incident electron energies. © 1990 The American Physical Society.