Structural and electronic properties of stable Aun (n = 2-13) clusters: A density functional study

All-electron scalar relativistic calculations have been performed to investigate the electronic structures of neutral gold clusters (Aun, n = 2-13) in the gas phase using density functional theory with the generalized gradient approximation. Full geometry optimizations of topologically different clusters and clusters belonging to different symmetry groups have been carried out. Binding energies, ionization potentials, electron affinities, and chemical hardness values are calculated and they are found to be comparable with the available experimental and theoretical results. The most stable structure of each of the cluster has a two-dimensional planar configuration. A three dimensional distorted Y shaped structure (4b) for Au4, a tri-capped triangle (6b), a chair (6f), and a see-saw structure (6j) for Au6, an eclipsed sandwich structure (7g) for Au7, a condensed trigonal bipyramid (9e) and a boat shaped structure (9f) for Au9, a staggered sandwich (11c) and an eclipsed sandwich structure (11d) for Au11, a ladderane structure (12d) for Au12, and a staggered (13d) and a distorted sandwich structure (13e) for Au13 are characterized for the first time in this work.