The basis set convergence of the Hartree–Fock energy for H3+, Li2 and N2

Abstract. By using completely optimized basis functions it is shown that the convergence of the Hartree–Fock energy for the H3+, Li2 and N2 molecules is significantly better described by exponential behavior than by inverse power dependence. This is the case both with respect to the number of basis functions of a given type and with respect to the highest angular momentum function included. The Hartree–Fock limit for H3+ is estimated to be −1.300372125 hartree.