On the bonding of Ga₂, structures of Ga<i>_n</i> clusters and the relation to the bulk structure of gallium

Gallium is an unusual metal, sometimes described as a molecular metal, composed of covalently bonded-dimers, with metallic bonding primarily in the plane perpendicular to the average alignment of the dimers. We analyse the interactions between Ga-2 molecules, and compare the calculated structures of small clusters to the complicated structure of the bulk. Both density functional and wavefunction-based methods are employed. The structures of small neutral clusters are shown to be remarkably similar to certain features of the bulk (alpha-Ga) structure. DFT calculations perform well in comparison to coupled cluster calculations in the size range considered. (C) 2010 Elsevier B.V. All rights reserved.