Structures of Fe3Pt3(CO)(15) (1), Fe2Pt5(CO)(12)(COD)(2) (2), Fe2Pt(CO)(8)(COD) (3) and Fe2Pt2(CO)(10) (4), as well as the driving forces for their formation from Fe(CO) (5) and Pt(COD)(2) (COD = 1,5-cyclooctadiene) have been computed at the PBE0-D3 level of density functional theory. Judged from a comparison of computation vs. experiment, this level should be well suited to study structures and thermochemistry of mixed FePt clusters, which may occur at the early stages of FePt nanoparticle synthesis. (C) 2011 Elsevier B.V. All rights reserved.