Nonorthogonal Tight-binding Study of the Geometries and Electronic Properties of Ge_n(n=2—20)Clusters

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Nonorthogonal Tight binding Study of the Geometries and Electronic Properties of Ge n (n =2-20) Clusters

The universal-parameter nonorthogonal tight-binding scheme proposed by Menon and Subbaswamy was used to optimize the geometrical structures, binding energies and electron affinities of small germanium clusters Ge_n (n =2-20). A complete agreement with available ab initio results from the lowest energy structures for Ge₂-Ge₆ was obtained and reasonable structures for these clusters were predicted and compared with those of corresponding silicon clusters in the range of n =7-20. The averaged discrepancy with experiments in binding energies for n =2-7 is about 6% and the calculated electron affinities agree well with the measured values in the range of n =2-8 as well.