Electronic and geometric structures of MoxSy and WxSy (x =1, 2, 4; y =1 12) clusters

Abstract

Electronic and geometric structures of MxSy (M = W, Mo; x=1,2,4;y=1 12) clusters have been studied using density functional theory calculations, and compared to experimental photoelectron spectra. For the metal atoms, an uptake of up to six sulfur atoms has been observed, which can be explained by the bonding of S3 - chains. A structural difference to the corresponding oxides is the preference of bridging sites for S, which might be the origin of the differences between the structures of bulk MO3 and MS2. For x=1,2 the HOMO LUMO gaps vary irregularly. For x=4, a large HOMO LUMO gap has been found for y=6,7, and 8 and the W4S6 and Mo4S6 clusters have been found to be magic with an extraordinarily high stability.