Density functional theory study of Au n Mn( n =1–8) clusters

Equilibrium geometries, relative stabilities, and magnetic properties of small Au n Mn ( n =1–8) clusters have been investigated using density functional theory at the PW91P86 level. It is found that Mn atoms in the ground state Au n Mn isomers tend to occupy the most highly coordinated position and the lowest energy structure of Au n Mn clusters with even n is similar to that of pure Au n+1 clusters, except for n =2. The substitution of Au atom in Au n+1 cluster by a Mn atom improves the stability of the host clusters. Maximum peaks are observed for Au n Mn clusters at n =2, 4 on the size dependence of second-order energy differences and fragmentation energies, implying that the two clusters possess relatively higher stability. The HOMO–LUMO energy gaps of the ground state Au n Mn clusters show a pronounced odd–even oscillation with the number of Au atoms, and the energy gap of Au 2 Mn cluster is the biggest among all the clusters. The magnetism calculations indicate that the total magnetic moment of Au n Mn cluster, which has a very large magnetic moment in comparison to the pure Au n+1 cluster, is mainly localized on Mn atom.