title: Accurate Spin-State Energies for Iron Complexes.
abstract: A critical assessment of the OPBE functional is made for its performance for the geometries and spin-states of iron complexes. In particular, we have examined its performance for the geometry of first-row transition-metal (di)halides (MnX2, FeX2, CoX2, NiX2, CuX, X=[F, Cl]), whose results were previously [J. Chem. Theory Comput. 2006, 2, 1282] found to be representative for a much larger and more diverse set of 32 metal complexes. For investigating the performance for spin ground-states of iron complexes, we examined a number of small iron complexes (Fe(II)Cl4(2-), Fe(III)Cl4(1-), Fe(II)Cl6(4-), Fe(III)Cl6(3-), Fe(II)CN6(4-), Fe(III)CN6(3-), Fe(VI)O4(2-), Fe(III)(NH3)6(3+)), benchmark systems (Fe(II)(H2O)6(2+), Fe(II)(NH3)6(2+), Fe(II)(bpy)3(2+)), and several challenging iron complexes such as the Fe(II)(phen)2(NCS)2 spin-crossover compound, the monopyridylmethylamine Fe(II)(amp)2Cl2 and dipyridylmethylamine Fe(II)(dpa)2(2+), and the bis complex of Fe(III)-1,4,7-triazacyclononane (Fe(III)((9)aneN3)2(3+). In all these cases OPBE gives excellent results.
authors.affiliation: Institució Catalana de Recerca i Estudis Avançats (ICREA), Pg. Lluís Companys 23, 08010 Barcelona, Spain, and Institut de Química Computacional and Departament de Química, Universitat de Girona, Campus Montilivi, 17071 Girona, Spain.
authors.forename: Marcel
authors.initials: M
authors.lastname: Swart