DISSOCIATING STATES OF THE H-3(-) SYSTEM

Single determinant Hartree-Fock calculations for the lowest singlet and triplet potential energy surfaces of the H3- system are presented over a broad range of isosceles triangular configurations of the nuclei. The addition of a diffuse s function to the four-term Gaussian expansion of Huzinaga for H(1s) together with p type polarization functions produces results which are in agreement with experiments on double electron capture by H3+ to form H3-. The present calculations predict that capture to the ground singlet state produces H 2 + H-, with a dissociation energy in reasonable agreement with the experimental findings. Capture to the triplet state is predicted to resulted in the three body dissociation H + H + H- with small dissociation energy. This is consistent with, but not positively confirmed by, the experimental data. © 1979 American Institute of Physics.