ACCURATE GROUND-STATE CALCULATIONS OF H-2(+) USING BASIS-SETS OF ATOM-CENTERED SLATER-TYPE ORBITALS

The variational method is used to find the ground-state energy of the molecular hydrogen ion, H-2+, by employing a linear combination of atomic orbitals (LCAO) of the Slater type, all with the same exponential parameter zeta. For the equilibrium position, R = 2 a.u., eight-digit accuracy was achieved using 21 orbitals on each nucleus, with the highest principal quantum number, N = 6. Beyond R = 50, thirteen-digit accuracy is obtained. The wave function is given for various LCAO at the equilibrium position. Strategies developed here will be useful in our studies of polyatomic nonlinear molecules.