Spin multiplicity and symmetry breaking in vanadium-benzene complexes

• Published in: Physical review letters Vol. 109; no. 5; p. 053001
• Main Authors: Horváthová, L, Dubecký, M, Mitas, L, Stich, I
• Format: Journal Article
• Language: English
• Published: United States American Physical Society 31-07-2012
• ISSN: 0031-9007; 1079-7114
• DOI: 10.1103/physrevlett.109.053001

We present accurate quantum Monte Carlo (QMC) calculations which enabled us to determine the structure, spin multiplicity, ionization energy, dissociation energy, and spin-dependent electronic gaps of the vanadium-benzene system. From total and ionization energy we deduce a high-spin state with vastly different energy gaps for the two spin channels. 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 calculations. 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.