Knowledge Bank

The self-consistent field molecular orbital method in the LCAO (linear combination of atomic orbitals) approximation is applied to the ground state of LiH and BH at a number of internuclear distances. Molecular orbitals have been constructed from 1s, 2s and $2ps$ orbitals on both centers. In these calculations both the LCAO coefficients and the screening constants of the atomic orbitals are optimized by the procedure given in Trans. Faraday Soc., 62, 1993 (1966). A full configuration interaction treatment has been applied to both the molecules at all internuclear distances to obtain the potential energy curves with the configurated wave functions. The molecular constants $\omega e,\omega pxe,Be,\alpha e$ and $De$ have been calculated from the computed potential energy curves and compared with the experimental data. The computed spectral results are more encouraging than hitherto reported in the literature from ab-initio calculations.