First principles study of structural, electronic and magnetic properties of SnGen(0, ±1) (n = 1–17) clusters

Abstract

The structures, relative stability and magnetic properties of pure Gen+1, neutral cationic and anionic SnGen (n = 1–17) clusters have been investigated by using the first principles density functional theory implemented in SIESTA packages. We find that with the increasing of cluster size, the Gen+1 and SnGen(0, ±1) clusters tend to adopt compact structures. It has been also found that the Sn atom occupied a peripheral position for SnGen clusters when n < 12 and occupied a core position for n > 12. The structural and electronic properties such as optimized geometries, fragmentation energy, binding energy per atom, HOMO–LUMO gaps and second-order differences in energy of the pure Ge n+1 and SnGen clusters in their ground state are calculated and analyzed. All isomers of neutral SnGen clusters are generally nonmagnetic except for n = 1 and 4, where the total spin magnetic moments is 2μb. The total (DOS) and partial density of states of these clusters have been calculated to understand the origin of peculiar magnetic properties. The cluster size dependence of vertical ionization potentials, vertical electronic affinities, chemical hardness, adiabatic electron affinities and adiabatic ionization potentials have been calculated and discussed.