AB INITIO CALCULATIONS ON LARGE BE CLUSTERS

Closed and open shell self-consistent field calculations are reported for clusters of 13, 19, 21, 33, and 39 Be atoms. Geometrical arrangements correspond to the second through sixth coordination spheres of a central Be atom with internuclear separations all derived from the lattice constants of the bulk metal (a=2.2866{\\AA}, c=3.5833{\\AA}). Each cluster possesses $D_{3h}$ point group symmetry. Nineteen electronic states of $Be_{13}{^{+}}$ and six states of $Be_{13}$ are discussed. Electric field gradients, nuclear electron potentials, second moments, and orbital energy diagrams are given for each cluster. The convergence of properties having origin at the central Be atom as a function of cluster size is slow and is not yet achieved with the inclusion of the sixth coordination sphere.