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

TL;DR

This study uses ab initio methods to simulate cadmium chalcogenide nanoclusters with various surface groups, providing insights into their structure and electronic properties relevant for bio-conjugate quantum dots.

Contribution

It introduces a computational approach combining HF and DFT to analyze the geometry and electronic effects of different terminating groups on cadmium chalcogenide clusters.

Findings

Terminating groups significantly influence cluster electronic structure.

Geometry optimization maintains tetrahedral symmetry.

Different cluster sizes and terminations affect electronic properties.

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.