Molecular-state cross-section calculations for H+Na⇄H−+Na+

Pseudopotential molecular-structure calculations have been performed on the NaH system to obtain the five lowest ${}_{}{}^1{}_{}{}^{}\mathrm{\Sigma }$ and two lowest ${}_{}{}^1{}_{}{}^{}\mathrm{\Pi }$ molecular states. The resulting eigenfunctions and eigenvalues were used in a perturbed-stationary-state calculation where electron-translation factors have been incorporated to first order in the collision velocity. The ion-pair formation cross section for H+Na→${\mathrm{H}}^{\mathrm{-}}$+${\mathrm{Na}}^{+}$ is found to have a maximum value of 3.3×${10}^{\mathrm{-}16}$ cm at 1 keV/amu. The ion-ion mutual neutralization cross section for ${\mathrm{H}}^{\mathrm{-}}$+${\mathrm{Na}}^{+}$→H+Na rises monotomically with decreasing collision velocity and is ∼1×${10}^{\mathrm{-}14}$ ${\mathrm{cm}}^2$ at energies from 0.1 to 5.0 keV/amu.