title: Charged vanadium-benzene multidecker clusters: DFT and quantum Monte Carlo study.
abstract: Using explicitly correlated fixed-node quantum Monte Carlo and density functional theory (DFT) methods, we study electronic properties, ground-state multiplets, ionization potentials, electron affinities, and low-energy fragmentation channels of charged half-sandwich and multidecker vanadium-benzene systems with up to 3 vanadium atoms, including both anions and cations. It is shown that, particularly in anions, electronic correlations play a crucial role; these effects are not systematically captured with any commonly used DFT functionals such as gradient corrected, hybrids, and range-separated hybrids. On the other hand, tightly bound cations can be described qualitatively by DFT. A comparison of DFT and quantum Monte Carlo provides an in-depth understanding of the electronic structure and properties of these correlated systems. The calculations also serve as a benchmark study of 3d molecular anions that require a balanced many-body description of correlations at both short- and long-range distances.
authors.affiliation: Institute of Physics, CCMS, Slovak Academy of Sciences, 84511 Bratislava, Slovakia.
authors.forename: K
authors.initials: K
authors.lastname: Tokár
authors.affiliation: Institute of Physics, CCMS, Slovak Academy of Sciences, 84511 Bratislava, Slovakia.
authors.forename: R
authors.initials: R
authors.lastname: Derian
authors.affiliation: Department of Physics, North Carolina State University, Raleigh, North Carolina 27695-8202, USA.
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