A computational study on geometries, electronic structures and ionization potentials of MSi15 (M=Cr, Mo, W) clusters by density functional method Original Research Article

Geometry optimization, electronic structures and ionization potentials of MSi15 (M=Cr, Mo, W) clusters are carried out under the constraint of well-defined point-group symmetry at the level of Vesko-Wilk-Nusair with generalized gradient approximation considering of Becke correction. The most stable structures are found for MSi15 (M=Cr, Mo, W) clusters. Stabilities of Si15, MSi15+ and MSi15 (M=Cr, Mo, W) clusters are presented and discussed. In addition, we comment on the electron transfer within the clusters. Theoretical results indicate that properties of Si15 cluster are influenced by the transitional metal (TM) (TM=Cr, Mo, W). Mulliken atomic net populations of TM in MSi15 and MSi15+ (M=Cr, Mo, W) clusters are reported, and the net populations of Si atoms are influenced by shifting electrons out of Si atoms to the TM (TM=Cr, Mo, W) atom. Charge transfer from impurity TM to Si atoms is the main factor that degrades the efficiency of the semiconductor.