Benchmarks and Reliable DFT Results for Spin Gaps of Small Ligand Fe(II) Complexes.
Suhwan SongMin-Cheol KimEunji SimAnouar BenaliOlle G HeinonenKieron BurkePublished in: Journal of chemical theory and computation (2018)
All-electron fixed-node diffusion Monte Carlo provides benchmark spin gaps for four Fe(II) octahedral complexes. Standard quantum chemical methods (semilocal DFT and CCSD(T)) fail badly for the energy difference between their high- and low-spin states. Density-corrected DFT is both significantly more accurate and reliable and yields a consistent prediction for the Fe-Porphyrin complex.