title: Quantum Monte Carlo Study of π-Bonded Transition Metal Organometallics: Neutral and Cationic Vanadium-Benzene and Cobalt-Benzene Half Sandwiches.
abstract: We present accurate quantum Monte Carlo (QMC) calculations that enabled us to determine the structure, spin multiplicity, ionization energy, dissociation energy, and spin-dependent electronic gaps of neutral and positively charged vanadium-benzene and cobalt-benzene systems. From total/ionization energy, we deduce a sextet (quintet) state of neutral (cationic) vanadium-benzene systems and quartet (triplet) state of the neutral (cationic) cobalt-benzene systems. Vastly different energy gaps for the two spin channels are predicted for the vanadium-benzene system and broadly similar energy gaps for the cobalt-benzene system. For this purpose, we have used a multistage combination of techniques with consecutive elimination of systematic biases except for the fixed-node approximation in QMC. Our results significantly differ from the established picture based on previous less accurate calculations and point out the importance of high-level many-body methods for predictive calculations of similar transition metal-based organometallic systems.
authors.affiliation: Institute of Physics, CCMS, Slovak Academy of Sciences , 84511 Bratislava, Slovakia.
authors.forename: L
authors.initials: L
authors.lastname: Horváthová
authors.affiliation: Institute of Physics, CCMS, Slovak Academy of Sciences , 84511 Bratislava, Slovakia.
authors.forename: M
authors.initials: M
authors.lastname: Dubecký
authors.affiliation: North Carolina State University , Department of Physics, Raleigh, North Carolina 27695, United States.
authors.forename: L
authors.initials: L
authors.lastname: Mitas
authors.affiliation: Institute of Physics, CCMS, Slovak Academy of Sciences , 84511 Bratislava, Slovakia.
authors.forename: I
authors.initials: I
authors.lastname: Štich