A Theoretical Study of Lithium-Doped Gallium Clusters by Density Functional Theory

The geometrical structures, stabilities, and electronic properties of Ga Li ( = 1 - 13) clusters were investigated within the density functional theory (DFT). The impurity lithium atom enhances the stability of Ga Li ( = 1 - 13) clusters, especially Ga Li ( = 9 - 13) compared to Ga = 9 - 14), that is at either apex position or side position. The dissociation energy, second-order energy differences, and the energy gaps between highest occupied and lowest unoccupied molecular orbital (HOMO-LUMO) indicate that the Ga Li, Ga Li, and Ga Li clusters are more stable within the studied cluster range. Moreover, the variation of the average bond length of Ga-Li is due to the surface effect, and the binding strength increases resulting from the increase of charge amount.