Geometric and Electronic Structures of Tc and Mn Clusters by Density Functional Calculations

The geometric structures of Tc2-Tc5 and Mn2-Mn8 clusters were optimized by the Amsterdam density functional method. The trimeric, tetrameric, and pentameric Tc clusters exhibit the equilibrium structures of isosceles triangle, tetrahedron, and square pyramid, respectively. The structures of the Mn clusters up to Mn4 are similar to those of the respective Tc clusters, while the Mn5, Mn6, Mn7, and Mn8 clusters have the distorted trigonal bipyramidal, distorted octahedral, pentagonal bipyramidal, and C2v structures, respectively. The Tc clusters are paramagnetic, while the Mn clusters are basically ferromagnetic.