Study of electronic properties, stabilities and magnetic quenching of molybdenum-doped germanium clusters: a density functional investigation

Abstract

Evolution of electronic structures, properties and stabilities of neutral and cationic molybdenum encapsulated germanium clusters (Mo@Ge_n, n = 1 to 20) has been investigated using the linear combination of atomic orbital density functional theory method with effective core potential. From the variation of different thermodynamic and chemical parameters of the ground state clusters during the growth process, the stability and electronic structures of the clusters is explained. From the study of the distance-dependent nucleus-independent chemical shifts (NICS), we found that Mo@Ge₁₂ with hexagonal prism-like structure is the most stable isomer and possesses strong aromatic character. Density of states (DOS) plots of different clusters is then discussed to explain the role of d-orbitals of the Mo atom in hybridization. Quenching of the magnetic moment of the Mo atom with increase in the size of the cluster is also discussed. Finally, the validity of the 18-electron counting rule is applied to further explain the stability of the metallo-inorganic magic cluster Mo@Ge₁₂ and the possibility of Mo-based cluster-assembled materials is discussed.