Density-functional study of Scn(n=2-16)clusters: Lowest-energy structures, electronic structure, and magnetism

摘要

The all-electron spin-polarized generalized gradient approximation (GGA) to the density-functional theory (DFT) has been used to determine the binding energies, ground-state structures, electronic structures, and magnetic properties of Scn clusters (n ≤16). The ground-state structures are closed compact arrangements and the clusters containing 4.5. 7. 10, and 13 atoms are found to be more stable than their neighboring clusters. The results tor the net magnetic moments and their evolution with size for the optimal clusters are in good agreement with experiment. Clusters favor lower spin configurations except for Sc2, Sc13, and Scl4 clusters, Sc13 cluster is a perfect icosahedral structure with a giant magnetic moment of 19μB and the maximum peak at Sc13 in experiment is reproduced by our calculations. Although our calculations overestimate some of the values, the size-dependent trend is generally consistent with the experimental pattern. The origin of the discrepancies arising in some cases is also discussed.