title: BaLn2Se4 (Ln = Er, Tm and Yb).
abstract: The compounds BaLn(2)Se(4) (Ln = rare-earth metal = lanthanide = Er, Tm and Yb), namely barium di(erbium/thulium/ytterbium) tetraselenide, crystallize in the orthorhombic space group Pnma in the CaFe(2)O(4) structure type. In this structure type, all atoms possess m symmetry. The Ln atoms are octahedrally coordinated by six Se atoms. A three-dimensional channel structure is formed by the corner- and edge-sharing of these LnSe(6) octahedra. The Ba atoms are coordinated to eight Se atoms in a bicapped trigonal-prismatic arrangement, and they occupy the channels of the three-dimensional framework.
authors.affiliation: Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208-3113, USA.
authors.forename: Daniel E
authors.initials: DE
authors.lastname: Bugaris
authors.forename: James A
authors.initials: JA
authors.lastname: Ibers