Density functional theory study of the structures and electronic properties of copper and sulfur doped copper clusters

The structures and electronic properties of copper and sulfur doped copper clusters have been systematically investigated by means of the CALYPSO structure searching method combined with density functional theory. According to optimized CunS geometries, the dominant growth pattern is described as one Cu atom being added on the Cun-1S clusters. The planar (C-2v) Cu2S cluster is the most stable geometries of CunS clusters. From n = 3, the doped systems show the appearance of three-dimensional (3D) geometries. In addition, the calculated HOMO-LUMO gaps are in the energy range of 1.42-2.96 eV, which make CunS clusters suitable candidates for renewable energy sources. At last, the molecular orbital energy, density of states, electrostatic potential and electron density deformation are also respectively analyzed for realizing the doped microscopic mechanism and providing strong support for essential theoretical and experimental research. (C) 2016 Elsevier B.V. All rights reserved.