Multichannel variational calculations of low-energy electron-molecule collisions: static exchange approximation

Kohn and inverse Kohn variational procedures are used to study the scattering of electrons by closed-shell diatomic molecules in the static exchange approximation. The trial wavefunctions are constructed from free particle, continuum static and bound orbitals. Variational corrections are obtained to the wavefunction as well as the reactance matrix. Various forms of the trial wavefunction are applied to collisions of electrons with H 2 , N 2 , LiH and CO, and the resulting eigenphases compares with exact static exchange results. For non-resonant symmetries, the method produces results within 10% of the exact results. Resonance widths and positions are predicted within 25% or better.