Alkalization of aluminum clusters

Equilibrium geometries, binding energies, ionization potentials, and electr on affinities of neutral and charged Al-n clusters (n less than or equal to 8) decorated with alkali atoms such as Li and K have been calculated using molecular orbital theory based on density functional formalism and general ized gradient approximation. While the electron affinities and the ionizati on potentials depend on size, no clear signatures of shell closings are fou nd in this size range. Similar studies on Al5Xm (X=Li, K, 1 less than or eq ual to m less than or equal to 4) also fail to provide any indication consi stent with shell closings. On the other hand, the ionization potentials and electron affinities of aluminum clusters decrease with the addition of alk ali atoms. The results are in good agreement with available experimental da ta. (C) 2000 American Institute of Physics. [S0021-9606(00)30728-0].