Density functional theory study of structural, electronic and CO adsorption properties of anionic Scn- (n=2-13) clusters

Clusters are aggregates or assemblies of atoms and have properties intermediate between bulk and molecules. Among transition metals, the studies regarding scandium clusters and in particular anionic scandium clusters are very scarce. Herein, geometric and electronic properties of anionic scandium clusters Sc-n(-) (n = 2-13) are studied by gradient-corrected exchange-correlation functional PBEPBE with LANL2DZ basis set. A number of possible geometries are taken into account for optimizations at different spin states. Furthermore, their relative stabilities have been evaluated by different parameters such as relative stability, binding energies and second order energy differences. Electronic properties are judged from vertical ionization energies, vertical electron affinities and HOMO-LUMO gaps. In addition, the role of pristine Sc-n(-) (n = 2-8) clusters as a CO adsorption surfaces are also evaluated. The larger interactions energies for Sc-CO clusters depict their higher stability in comparison to Sc-OC interaction mode.