Theoretical Study on the Growth Behavior and Photoelectron Spectroscopy of Lanthanum-Doped Silicon Clusters LaSin0/- (n=6-20)

The growth behavior and electronic properties of the lowest energy structures of neutral LaSin (n=6-20) and their anions were explored by means of the ABCluster global structure searching strategy combined with the mPW2PLYP double-hybrid density functional. The results revealed that the growth behavior of the lowest energy structures of anionic LaSi (n=10-20) clusters choose La-linked two silicon subclusters to La-encapsulated in silicon cages. For neutral LaSin (n=6-20), the growth behavior of the lowest energy structures from substitutional structure to linked motifs and finally to encapsulated configurations occurs at n=14 and 20, respectively. The simulated photoelectron spectroscopy, adiabatic electron affinities, vertical detachment energies, relative stability and HOMO-LUMO energy gaps were presented. Analyses of HOMO-LUMO energy gaps, relative stability, and chemical bonding reveal that the LaSi20- possesses ideal thermodynamic and chemical stability in a high I-h-symmetry endohedral motif, which can turn it into suitable constitutional units for cluster-assembled nanomaterials.