title: Ab initio multiconfiguration reference perturbation theory calculations on the energetics of low-energy spin states of iron(III) porphyrins.
abstract: Although a major goal of inorganic spectroscopy is to determine the energetics of the low-lying spin states of transition metal complexes, surprisingly little has been accomplished in this respect by means of accurate ab initio calculations. Against this context, we present ab initio multiconfiguration reference perturbation theory (CASPT2) calculations with large basis sets on the low-lying spin states of Fe(III)(P)Cl and [Fe(P)Cl](+) (P(2-)=porphinato). The CASPT2 results on the energetics of various low-lying spin states studied differ significantly, sometimes even dramatically, from those obtained from density functional theory calculations.
authors.affiliation: Department of Chemistry, Faculty of Science, University of Troms, 9037 , Tromsø, Norway. abhik@chem.uit.no.|San Diego Supercomputer Center, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA, 92093, USA. abhik@chem.uit.no.
authors.forename: Abhik
authors.initials: A
authors.lastname: Ghosh
authors.affiliation: San Diego Supercomputer Center, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA, 92093, USA.
authors.forename: B Joakim
authors.initials: BJ
authors.lastname: Persson
authors.affiliation: San Diego Supercomputer Center, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA, 92093, USA. P.R.Taylor@warwick.ac.uk.
authors.forename: Peter R
authors.initials: PR
authors.lastname: Taylor
mesh_terms: D055598:Chemical Phenomena; D002627:Chemistry, Physical; D004563:Electrochemistry; D004735:Energy Transfer; D007501:Iron / Q000737:chemistry*; D008280:Magnetics; D008968:Molecular Conformation; D011166:Porphyrins / Q000737:chemistry*
chemical_list: D011166:Porphyrins; D007501:Iron