Theoretical methods based on density functional theory have been employed to analyze the exchange interactions in an Fe-6 Complex. The calculated exchange coupling constants are consistent with an S = 5 ground state and agree well with those reported previously for other Fe-III polynuclear complexes. Ferromagnetic interactions may appear through exchange pathways formed by two bridging hydroxo or oxo ligands. (c) 2006 Elsevier B.V. All rights reserved.