ENERGETICS AND STRUCTURES OF ALUMINUM-LITHIUM CLUSTERS

Energetics and structures of small aluminum-lithium clusters were investigated using structure-minimization and dynamic simulated annealing on the electronic Born-Oppenheimer surface, calculated via the local-spin-density-functional method in conjunction with nonlocal pseudopotentials. It is suggested that evolutionary patterns of electronic structure, energetics, and binding in AlLi(n) clusters may be analyzed within a framework where atomic-based characteristics, associated mainly with closing of the Al 3p shell, dominate for n less-than-or-equal-to 5, while a perturbed delocalized electronic cluster-shell pattern, containing an AlLi5 ''core,'' develops for larger clusters (i.e., for n greater-than-or-equal-to 6). The ground-state electronic and geometrical structures of AlLi(n) clusters, as well as those of Al2Li10 which may be viewed as two slightly distorted AlLi5 units bonded to each other, are discussed.