The high stability of boron-doped lithium clusters Li5B, Li6B+/− and Li7B: A case of the phenomenological shell model

A quantum chemical investigation of the clusters Li5B, Li6B+, Li6B− and Li7B was performed using the DFT, MP2 and CCSD(T) methods. The high symmetry structures (C4v, 1A1), (Oh, 1A1g) and (D5h, 1 A 1 ′ ) turnout to be the global minima for Li5B, Li6B+ and Li7B, respectively. These clusters are predicted to be highly stable species with large vertical ionization energies, and large HOMO–LUMO gaps. Chemical bonding of clusters was probed using an electron localizability indicator (ELI) which indicates a large aromatic character. The high stability of these clusters can be accounted for by the phenomenological shell model.