Structures, stabilities, and electronic properties of F-doped Si_n (n=1～12) clusters：Density functional theory investigation

The geometries, stabilities, and electronic properties of FSi_n (n=1～12) clusters are systematically investigated by using first-principles calculations based on the hybrid density-functional theory at the B3LYP/6-311G level. The geometries are found to undergo a structural change from two-dimensional to three-dimensional structure when the cluster size n equals 3. On the basis of the obtained lowest-energy geometries, the size dependencies of cluster properties, such as averaged binding energy, fragmentation energy, second-order energy difference, HOMO–LUMO (highest occupied molecular orbital–lowest unoccupied molecular orbital) gap and chemical hardness, are discussed. In addition, natural population analysis indicates that the F atom in the most stable FSi_n cluster is recorded as being negative and the charges always transfer from Si atoms to the F atom in the FSi_n clusters.