Gaussian orbital calculations of solids. Crystalline lithium hydride

The floating spherical Gaussian orbital model of molecular structure presented by Frost is extended to the calculation of an infinite crystal. For the calculation the crystal is divided into an inner region which contains a limited number of sites and a far-field region which includes the remaining sites in a 3-dimensional infinite crystal. The numerical results for LiH crystal are obtained with an inner region of 46 sites. The internuclear distance for LiH crystal is found to be only 3 % smaller than the experimental distance, while the heat of sublimation is calculated to be 24 % above the experimental value.