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

The geometrical structures, stabilities, and electronic properties of Ga_nLi (n = 1–13) clusters were investigated within the density functional theory (DFT). The impurity lithium atom enhances the stability of Ga_nLi (n = 1–13) clusters, especially Ga_nLi (n = 9–13) compared to Ga_n (n = 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 Ga₇Li, Ga₉Li, and Ga₁₁Li 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.