Solution of the Hartree–Fock equations for polyatomic molecules by a pseudospectral method

A pseudospectral code for general polyatomic molecules has been developed using Gaussian basis functions. As an example, the water molecule is studied using a 6-31G** basis set. Quantitative agreement with conventional calculations is obtained for the equilibrium geometry, total energy, first ionization potential, and vibrational force constants. Timing results for a vectorized version of the code (run on a Cray X-MP) indicate that for large molecules, rate enhancements of Hartree–Fock self-consistent field calculations of order 103 can be achieved.