We present a systematic theoretical study about Inn clusters with n=1-10. We explore the lowest-energy structures and investigate their geometric and electronic properties including electronic affinity (EA), ionization potential (IP), HOMO-LUMO gap, second difference of cluster total energy (∆2E) and spin density (SD) using the DFT method with the B3LYP and M06 functionals, and LANL2DZ.
As a measure of the complexs relative stability, we calculate the binding energy per atom (Eb) and we observe that increases together with the size of the cluster (up to n=7) and then remains constant at 1,27 eV/atom. Besides, the same lowest-energy structures are obtained with B3LYP and M06, except for In3 and In5.
The analysis of EA and IP is reliable with previous DFT results for other metals and calculations using B3LYP present better results according to the bibliography. The HOMO-LUMO gap exhibit odd-even oscillations. For both functionals are observed similar behaviors up to n=6, but do not correlate with the electron-pairing effect according to previous works. For n>6, with M06, maximums in even-clusters are obtained, indicating a more consistent result. Regardless the functional chosen, the ∆2E it’s higher for In3 and In8, indicating that this clusters are most stables than their neighbors. Finally the SD is strongly dependent on the shape and size of the cluster: small changes in the structure cause large changes in the SD and when the number of atoms increases, the reactivity decreases because the spin is scattered over a larger surface.