Density functional study on the growing patterns and reactivity of small Sin and MSi(n-1) (M = Ni, Cu, Pd, Ag) aggregates

CARLA LORENA HEREDIA; VERÓNICA FERRARESI CUROTTO

La plata, Buenos Aires

Congreso; 4th Workshop on Novel Methods for Electronic Structure Calculations, and First Southamerican Congress on Materials; 2011

Facultad de ingeniería, UNLP

Structural features of small Sin (n = 10) clusters are studied within the framework of the density functional theory following a systematic growing mechanism. Various novel structures are found and, in other cases, good agreement exists with results already reported by other authors. It is found that Sin (n=10) clusters tend to grow mainly towards three-dimensional structures. The growing patterns could be explained mainly in terms of nucleophilic attacks up to the size of eight atoms and in terms of electrophilic attacks for larger sizes. This structures are also used as parent clusters to obtain MSi(n-1) (M = Ni, Cu, Pd, Ag) aggregates. It is found that atomic charges derived from electrostatic potentials allow rationalizing the growing pattern and the reactivity characteristics of all clusters. Moreover, we present the characterization of such clusters through global reactivity descriptors, chemical potential, chemical hardness and electrophilicity index, computed using vertical electronic affinities and ionization potentials. In addition, we compare HOMO-LUMO energy gaps in order to understand which of the metal impurities contributes the most to increase reactivity in Sin (n = 10) aggregates.