FAST HARTREE-FOCK CALCULATIONS BY SIMULATED DYNAMICS .2. AN EFFICIENT, STABLE, AND ACCURATE ALGORITHM FOR MOLECULES

We have developed a computational routine for performing Hartree-Fock calculations in molecules by simulated dynamics. For fixed molecular g eometry calculations, the routine is faster and more stable than the s tandard self-consistent-field approach. It further admits the simultan eous optimization of the electronic wave functions and geometry, using reliable Hellmann-Feynman forces with nuclei-centered Gaussian orbita ls for the nuclear motion. We also investigate the role of nearly line ar dependence of the basis set on this type of calculation, so far unr ecognized. We present applications to some diatomic hidrides and com a re our results with those from GAUSSIAN92.