Structures and properties of Si6N8 clusters: Genetic algorithm and density functional theory approach

Genetic algorithm was combined with the semi-empirical quantum chemical PM3 method (GA+PM3) to scan the potential energy surface of cluster. The resulting isomers found by the GA+PM3 approach were then further optimized at the first principle level using Density Functional Theory (DFT) to obtain the optimal geometry and electronic structure for each cluster. This methodology was applied to investigate Si6N8 clusters. The electric charges and bond properties, along with the IR and Raman frequencies, polarizabilities and hyperpolarizabilities, of Si6N8 clusters were analyzed in detail.