Theoretical exploration of the structural evolution and electronic properties of LiAln−/0 (n = 3–20) clusters

We performed a theoretical study on the structures and electronic properties of LiAl_n^−/0 (n = 3–20) clusters using a hybrid global optimization algorithm and density functional theory (DFT). The ground-state structures of LiAl_n⁻ (n = 3–15) anions were confirmed based on good matching results between simulated and experimental photoelectron spectra. These LiAl_n^−/0 (n = 3–20) clusters prefer to adopt Al_n clusters as the structural motifs with the Li atom absorbed on the surface. The neutral LiAl_n clusters maintain identical structural configurations with their anionic counterparts for most sizes, with the notable exception for sizes n = 17–20. In LiAl_n^−/0 clusters, Li always contributes electrons to the Al_n. Doping Li atom has significant effects on the electronic properties of Al_n clusters. Neutral AMAl₁₃ (AM = Li Na, K, Rb, Cs) and anionic Al₁₃⁻ are confirmed as superatoms with the electronic configuration of (1S)²(1P)⁶(1D)¹⁰(2S)²(1F)¹⁴(2P)⁶, as same as that of the gallium-based counterparts.