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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 Mn cluster, which has a very large magnetic moment in comparison to the pure Au(n+1) cluster, is mainly localized on Mn atom. (C) 2010 Elsevier Ltd. All rights reserved.