UNIGE document Scientific Article
previous document  unige:24068  next document
add to browser collection

Accurate Spin-State Energetics of Transition Metal Complexes. 1. CCSD(T), CASPT2, and DFT Study of [M(NCH)6]2+ (M = Fe, Co)

Robinson, Timothy W.
Published in Journal of Chemical Theory and Computation. 2012, vol. 8, no. 11, p. 4216-4231
Abstract Highly accurate estimates of the high-spin/low-spin energy difference ΔEHLel in the high-spin complexes [Fe(NCH)6]2+ and [Co(NCH)6]2+ have been obtained from the results of CCSD(T) calculations extrapolated to the complete basis set limit. These estimates are shown to be strongly influenced by scalar relativistic effects. They have been used to assess the performances of the CASPT2 method and of 30 density functionals of the GGA, meta-GGA, global hybrid, RSH and double-hybrid types. For the CASPT2 method, the results of the assessment support the proposal [Kepenekian, M.; Robert, V.; Le Guennic, B. J. Chem. Phys.2009, 131, 114702] that the ionization potential–electron affinity (IPEA) shift defining the zeroth-order Hamiltonian be raised from its standard value of 0.25 au to 0.50–0.70 au for the determination of ΔEHLel in Fe(II) complexes with a [FeN6] core. At the DFT level, some of the assessed functionals proved to perform within chemical accuracy (±350 cm-1) for the spin-state energetics of [Fe(NCH)6]2+, others for that of [Co(NCH)6]2+, but none of them simultaneously for both complexes. As demonstrated through a reparametrization of the CAM-PBE0 range-separated hybrid, which led to a functional that performs within chemical accuracy for the spin-state energetics of both complexes, performing density functionals of broad applicability may be devised by including in their training sets highly accurate data like those reported here for [Fe(NCH)6]2+ and [Co(NCH)6]2+.
Full text
Article (Published version) (563 Kb) - document accessible for UNIGE members only Limited access to UNIGE
Research group Groupe Hauser
(ISO format)
LAWSON DAKU, Latevi Max et al. Accurate Spin-State Energetics of Transition Metal Complexes. 1. CCSD(T), CASPT2, and DFT Study of [M(NCH)6]2+ (M = Fe, Co). In: Journal of Chemical Theory and Computation, 2012, vol. 8, n° 11, p. 4216-4231. doi: 10.1021/ct300592w https://archive-ouverte.unige.ch/unige:24068

537 hits

0 download


Deposited on : 2012-11-19

Export document
Format :
Citation style :