Knowledge Bank

The interface between bulk and cluster-like behavior has been investigated via ab initio calculations on large clusters of up to 135 Be atoms. Calculations have been carried out at the Hartree-Fock level of approximation. The largest cluster corresponds to sixteen coordination spheres of a central Be with internuclear separations derived from the lattice constants of the bulk metal. Ab initio effective core potentials are employed to replace the effects of the Is electrons reducing the complexity of the calculations. In addition, the use of full $D3h$ symmetry results in a substantial reduction in the number of two-electron integrals that must be computed and processed. Properties calculated for selected states include binding energy, electric field gradient, nuclear-electron potential, diamagnetic shielding constant, second moments, quadrupole moment, and Mulliken populations. In addition, density of states and valence-electron density distribution analyses have been performed and are compared to those of bulk Be metal.