title: Structures of small bismuth cluster cations.
abstract: The structures of bismuth cluster cations in the range between 4 and 14 atoms have been assigned by a combination of gas phase ion mobility and trapped ion electron diffraction measurements together with density functional theory calculations. We find that above 8 atoms the clusters adopt prolate structures with coordination numbers between 3 and 4 and highly directional bonds. These open structures are more like those seen for clusters of semiconducting-in-bulk elements (such as silicon) rather than resembling the compact structures typical for clusters of metallic-in-bulk elements. An accurate description of bismuth clusters at the level of density functional theory, in particular of fragmentation pathways and dissociation energetics, requires taking spin-orbit coupling into account. For n = 11 we infer that low energy isomers can have fragmentation thresholds comparable to their structural interconversion barriers. This gives rise to experimental isomer distributions which are dependent on formation and annealing histories.
authors.affiliation: Institut für Physikalische Chemie, Karlsruher Institut für Technologie, Fritz-Haber-Weg 2, 76131 Karlsruhe, Germany.
authors.forename: Rebecca
authors.initials: R
authors.lastname: Kelting
authors.forename: Alexander
authors.initials: A
authors.lastname: Baldes
authors.forename: Ulrike
authors.initials: U
authors.lastname: Schwarz
authors.forename: Thomas
authors.initials: T
authors.lastname: Rapps
authors.forename: Detlef
authors.initials: D
authors.lastname: Schooss
authors.forename: Patrick
authors.initials: P
authors.lastname: Weis
authors.forename: Christian
authors.initials: C
authors.lastname: Neiss
authors.forename: Florian
authors.initials: F
authors.lastname: Weigend
authors.forename: Manfred M
authors.initials: MM
authors.lastname: Kappes