Ligand effects on Si_xL_y cluster structures with L = H and F

Abstract

The global minima for Si₂L₄, Si₇L₁₄, Si₈L₁₄, Si₁₀L₁₆ and Si₁₀ L₁₄ with L =  H and F are determined at the B3LYP density functional theory level by using the cluster genetic algorithm (CGA) developed in our laboratory. We find the H and F ligands to produce very different low-energy Si _x L _y structures. In general, Si _x H _y prefers to form structures with H fairly evenly distributed over the Si atoms, whereas, Si _x F _y favours forming structures containing SiF₃ side groups. These SiF₃ side groups result in the Si _x F _y global minima having smaller Si rings with higher ring strain present than in the Si _x H _y global minima structures.

Acknowledgement

We are grateful for the generous supply of computer time provided by the Maui High Performance Computing Center.