The Cu6Sc+ cation was detected experimentally as a stable bimetallic cluster [N. Veldeman, T. Holtzl, S. Neukermans, T. Veszpremi, M. T. Nguyen, Phys. Rev. A. 76 ( 2007) 011201]. DFT calculations using the BP86 functional with various basis sets yield a D-3h tricapped tetrahedron shaped structure as the most stable isomer. This cluster has a (SP6)-P-2 electron configuration with a closed electronic shell, and its electrons tend to localize around Sc thereby fully occupying electron shell orbitals. Stability, high symmetry, and the NICS show that this cluster is aromatic. The neutral Cu5Sc cluster has the same electron configuration as Cu6Sc+. In agreement with qualitative predictions, DFT computations show that the C-4v octahedron-shaped Cu5Sc cluster features a closed electronic structure and an aromatic character. (C) 2009 Elsevier B. V. All rights reserved.