title: Li9Al4Sn5as a new ordered superstructure of the Li13Sn5type.
abstract: Alloys from the ternary Li-Al-Sn system have been investigated with respect to possible applications as negative electrode materials in Li-ion batteries. This led to the discovery of a new ternary compound, a superstructure of the Li13Sn5binary compound. The ternary stannide, Li9Al4Sn5(nonalithium tetraaluminium pentastannide; trigonal, P-3m1, hP18), crystallizes as a new structure type, which is an ordered variant of the binary Li13Sn5structure type. One Li and one Sn site have -3m. symmetry, and all other atoms occupy sites of 3m. symmetry. The polyhedra around all types of atoms are rhombic dodecahedra. The electronic structure was calculated by the tight-binding linear muffin-tin orbital atomic spheres approximation method. The electron concentration is higher around the Sn and Al atoms, which form an [Al4Sn5]m-polyanion.
authors.affiliation: Department of Inorganic Chemistry, Ivan Franko Lviv National University, Kyryla and Mefodiya str. 6, 79005 Lviv, Ukraine.
authors.forename: Volodymyr
authors.initials: V
authors.lastname: Pavlyuk
authors.affiliation: Department of Inorganic Chemistry, Ivan Franko Lviv National University, Kyryla and Mefodiya str. 6, 79005 Lviv, Ukraine.
authors.forename: Grygoriy
authors.initials: G
authors.lastname: Dmytriv
authors.affiliation: Department of Inorganic Chemistry, Ivan Franko Lviv National University, Kyryla and Mefodiya str. 6, 79005 Lviv, Ukraine.
authors.forename: Ivan
authors.initials: I
authors.lastname: Tarasiuk
authors.affiliation: Institute for Applied Materials, Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, D-76344 Eggenstein-Leopoldshafen, Germany.
authors.forename: Helmut
authors.initials: H
authors.lastname: Ehrenberg
keywords: computational chemistry; crystal structure; electronic structure; lithium intermetallic; lithium-ion batteries; negative electrode material; ternary Li–Al–Sn system