Structure and stability of aluminium doped lithium clusters (LinAl0/+, n=1-8): a case of the phenomenological shell model

Quantum chemical calculations are performed on the aluminium doped lithium clusters LinAl at both neutral and cationic states using the DFT/B3LYP and CCSD(T) methods in conjugation with the aug-cc-pVaZ (a = D,T,Q) basis sets. The global minima are located and the growth mechanism is established. The electronic structure, geometrical parameters and energetic properties, such as average binding energy E-b, second difference of energy D 2 E, adiabatic and vertical ionization energy, and dissociated enthalpy, are evaluated using the coupled-cluster CCSD(T) method, whose energies are extrapolated to the complete basis set limit (CBS). The high stability of Li5Al, Li7Al, Li6Al+ and Li8Al+ that have the "magic numbers" of valence electrons, can be understood using the phenomenological shell model.