Thirteen-atom clusters: Equilibrium geometries, structural transformations, and trends in Na, Mg, Al, and Si

We report the results of an extensive structural study of Na13, Mg13, Al13, and Si13 carried out with the Car-Parrinello method. Several and mostly unforeseen noncrystalline structures are discovered to characterize the low portion of the potential energy surface. Crystalline structures are shown either to correspond to high-energy local minima or to be highly unstable. The low-energy structural pattern appears to change significantly from one element to the other. Specific characteristics as well as trends are discussed. © 1992 American Institute of Physics.