Magnetism in small rhodium clusters under structural deformations

The effect of hydrostatic and axial deformations on the magnetic and electronic properties of small Rh clusters was studied. The electronic properties were calculated using a self-consistent spd tight-binding Hamiltonian within the unrestricted Hartree-Fock approximation. For hydrostatic deformations, the magnetic moment of the clusters increases with bond-length in a steplike fashion. On the other hand, axial distortions affect the magnetism of the clusters in a more complex manner that cannot always be related in a simple way to geometrical parameters. An analysis of the paramagnetic density of states is performed in order to elucidate the physical origin of our results. (C) 2003 Elsevier B.V. All rights reserved.