Ab-initio calculations of cadmium sulfide clusters—fragments of thiolate complexes

Abstract

A series of clusters constructed from cadmium and sulfur atoms beginning from a central cadmium is considered as fragments of the bigger cadmium sulfide clusters bounded by the shell of thiolate ligands. The sequence of these clusters includes CdS 4, CdS 4H 4, Cd 13S 4, Cd 13S 16, Cd 13S 16H 12. Hydrogen atoms are used to simulate thiolate ligands. The MO LCAO RHF SCF calculations were performed for ground states, and equilibrium geomerties were obtained which show the essential difference in the Cd–S interatomic distances for inner and external bonds. Energies of the first allowed electronic transition vary non-monotonously from 9.86 eV for the smallest clusters to 3.39 eV for Cd 13S 16H 12 4+. Cd 13S 16–clusters are proposed as possible intermediates in the growth of large observed structures.