A Comparative DFT and CCSD study of Spin-Crossover in Mononuclear Transition Metal Complexes
Luis-Antonio Soriano-Agueda1 , Álvaro Vázquez-Mayagoitia2 and Alberto Vela1
1 Departamento de Química, Centro de Investigación y de Estudios Avanzados, Av.
Instituto Politécnico Nacional 2508, D. F. 07360 México, México.
2 Computational Sciences Division. Argonne National Laboratory, Lemont, Illinois
We present a study of spin-crossover (SCO) in mononuclear transition metal complexes containing Mn, Fe, and Co. Results obtained with several exchange-correlation density functional approximations (DFAs) are presented and compared with those calculated with coupled cluster theory with single and double excitations (CCSD). The range-separated DFAs, especially ωB97X, yield values closest to the CCSD results. We also show that the energy differences provided by the density-corrected approach proposed by Sim and Burke are in very good agreement with the range-separated and CCSD results. We also discuss issues of the multiplicity of the high-spin state in these complexes.