title: Mixed valence character of anionic linear beryllium chains: a CAS-SCF and MR-CI study.
abstract: A theoretical investigation on the mixed valence behavior, or bistability, of a series of anionic linear chains composed of beryllium atoms is presented. Calculations on Be(N)- (with N = 7, ..., 13) were performed at CAS-SCF and MR-CI levels by using an ANO basis set containing 6s4p3d2f contracted orbitals for each atom. Our results show a consistent gradual shift between different classes of mixed valence compounds as the number of beryllium atoms increases, from strong coupling (class III) toward valence-trapped (class II). Indeed, in the largest cases (N > 10), the anionic chains were found to become asymptotically closer to class I, where the coupling vanishes. The intramolecular electron-transfer parameters V(ab), E(barr), and E(opt) were calculated for each atomic chain. It is shown that the decrease of V(ab) with increasing N follows an exponential pattern.
authors.affiliation: Dipartimento di Chimica, Università di Ferrara, Via Borsari 46, I-44100 Ferrara, Italy.
authors.forename: Mariachiara
authors.initials: M
authors.lastname: Pastore
authors.forename: Antonio
authors.initials: A
authors.lastname: Monari
authors.forename: Stefano
authors.initials: S
authors.lastname: Evangelisti
authors.forename: Thierry
authors.initials: T
authors.lastname: Leininger
mesh_terms: D001608:Beryllium / Q000737:chemistry*; D004579:Electron Transport; D011789:Quantum Theory
chemical_list: D001608:Beryllium