A DFT Study of Geometric Structure and Stability of Iron-Silicon Clusters

摘要

Geometric structures of Fe_(6-x)Si_x(.x=l-5) clusters have been systematically studied at the BPW91 level by density-functional theory(DFT). Calculated results show that the Fe atoms of the lowest-energy structures of Fe_(6-x)Si_x clusters tend to go together, and Si atoms tend to occupy surface site bonding with iron atoms as many as possible. Further, we analyze the stability of the lowest-energy structures of Fe_(6-x)Si_x clusters, and the corresponding results of the HOMO, LUMO as well as the HOMO-LUMO energy gap show that the Fe-5Si and Fe_4Si_2 clusters have special stability.