α-Gallium: An alternative to the boron structure

Abstract

The well-known α-Ga structure is attributed to a structure which is built up from open polyhedral fragments, and is strongly related to the closed polyhedral boron clusters B. The one short Ga-Ga bond corresponds to the terminal bonds in closo-boranes. Extended Hiickel calculations support this model and show that also the α-Ga structure is an appropriate covalent three-electron arrangement and is not electron-deficient.