One- and Two-Center Calculations on the Lowest-Lying Π States of HeH+

Abstract

Accurate two‐center calculations using a basis set of elliptical orbitals are made on the lowest‐lying singlet and triplet‐Π states of HeH⁺. The calculated dissociation energies of these states are 0.234 eV for the singlet and 0.147 eV for the triplet. Single‐center wavefunctions for these two states are also computed at the equilibrium internuclear separation predicted by the two‐center results (8.05 bohrs for the singlet and 7.67 bohrs for the triplet). The differences in the energies of the one‐ and two‐center calculations are 144 cal and 94 cal for the singlet and triplet, respectively. Expectation values of several operators are given along with calculated values of the spectroscopic constants.