A Quantum-Chemical Simulation of the Cadmium Chalcogenide Clusters Terminated with Hydrogen and Simple Functional Groups

Abstract

Ab initio calculations of cadmium chalcogenide nanoclusters with terminating groups (H, O, N, and C atoms bound to the surface sulfur) are considered as a simulation for the species produced in typical synthesis of bio-conjugates with luminescent quantum dots. The approaches based on the Hartree-Fock (HF) method and density functional theory (DFT) are used assuming geometry optimization keeping the tetrahedral symmetry. The geometry and electronic structure of CdX (X=S, Se, Te) clusters with size up to Cd17 (HF) and Cd4 (DFT) bound with hydrogen and -OH, -NH2, -CH3, and -CH2CH3 groups are calculated and the effects of the terminating groups upon core clusters are discussed.