title: Computational investigation of the Bi lone-pairs in monoclinic bismuth triborate BiB3O6.
abstract: The Bi-O interactions and the Bi lone-pairs in monoclinic BiB3O6 are investigated with gradient-corrected hybrid B3PW density functional theory within the Gaussian-orbital-based CO-LCAO scheme. The Bi 6s and O 2p orbitals contribute to both bonding and antibonding interactions below the Fermi level. The stereochemical activity of the Bi lone-pairs was found to have a major origination from the primary interaction for the Bi 6s-O 2p antibonding orbital. The Bi 6p orbitals are not critically responsible for the non-spherical shape of the Bi lone-pairs, although they indeed participate into the secondary interaction with the Bi 6s-O 2p antibonding states. It is also suggested that O 2p components within the Bi lone-pairs are dominantly significant for the optical responses of BiB3O6 over the Bi 6s components.
authors.affiliation: Institute of Theoretical Chemistry, University of Cologne, Greinstr. 4, Cologne, Germany. jyang0@uni-koeln.de
authors.forename: Jun
authors.initials: J
authors.lastname: Yang
authors.forename: Michael
authors.initials: M
authors.lastname: Dolg