Theoretical study on the relationship between the geometric change and the s-p hybridization formation of LiAl_n^- clusters (n = 3-13)

The relationships between the geometric and electronic structures, and photoelectron spectra (PES) of LiAl_n^- (n = 3-13) clusters were investigated. The ground and low-lying states geometries were optimized using B3LYP calculation. The assignment for large PES peaks was performed on the basis of calculated adiabatic detachment energies (ADE) and vertical detachment energies (VDE) values. PES peaks in Figure 2 of the clusters smaller than n = 6 are arose mostly from 3p of Al and those larger than n = 9 are 3s-3p (s-p) of Al. This peak pattern change occurs due to the s-p hybridization with the change in the geometric features. It was suggested that the high coordinated Al atom(s) in the Al framework and Li atom play an important role in forming the s-p hybridization at n ≥ 9.