Electron-impact state-to-state resolved cross sections and rate coefficients for the X(v) → A(v′) excitation in BeH molecules

Abstract

Electron-impact cross sections are calculated for the v → v′ transitions occurring between the vibrational levels of the two X 2Σ+ and A 2Π electronic states of the BeH molecule. The calculations are performed with the R-matrix method for a purely vertical electronic transition for energies from threshold to 15 eV, and by using a modified version of the Mott and Masssey approximation to extend the calculations to high energies and to vibrational excitations. Rate coefficients are also calculated for the same transitions. The calculated v–v′ selective cross sections and rate coefficients both satisfy distinct scaling relationships, which can be represented in a simple analytic form.