Nuclear dynamics of the H2- collision complex beyond the local approximation: associative detachment and dissociative attachment to rotationally and vibrationally excited molecules.

**Abstract:**

An improved nonlocal resonance model for the
description of the nuclear dynamics of the H-2(-) collision complex is

developed. The model is based on the ab initio
electron-H-2 scattering data of Berman et al at short internuclear

distances, the ab initio data of Senekowitsch
et al for the bound (2)Sigma(u)(+) state of H-2(-) at intermediate

distances, and exhibits the correct polarization
interaction at large internuclear distances. Cross sections for associative

detachment (AD) and dissociative attachment (DA)
to rotationally and vibrationally excited molecules were calculated

for a wide range of energies and angular momenta
with full inclusion of nonlocal effects. The calculated AD rate constant

at 300 K is 3.8 x 10(-9) cm(3) s(-1), which is
significantly larger than the experimental value reported by Schmeltekopf

et al. A series of narrow low-energy orbiting
resonances was found in the AD cross section. Our results compare well

with previous calculations of DA cross sections
within the nonlocal resonance model. The DA cross section for

vibrationally and rotationally hot H-2 (T = 1400
K) has been calculated and compared with the experimental data of

Allan and Wong. It is demonstrated that the local-complex-potential
approximation is an excellent approximation for the

associative detachment process, whereas it fails
severely for the DA process in H-2.