Optimum atomic orbital exponents for molecular wave functions

Abstract

Calculated potential energy curves have been obtained for H₂ and LiH using valence bond wave functions based on a minimum basis set of Slater type orbitals. The orbital exponents have been optimized at all internuclear distances and the results compared with the curves obtained using best atom and best equilibrium-molecule exponents. The vibration frequencies obtained from the best R_e exponents are appreciably larger than those from the calculations in which the exponents are optimized at all R.