Na₂₉Zn₂₄Sn₃₂: A Zintl Phase Containing a Novel Type of {Sn₁₄} Enneahedra and Heteroatomic {Zn₈Sn₄} Icosahedra

Abstract

A new type of polyhedron: An {Sn14} enneahedron, which can be derived from a trigonal bipyramid by truncating the three equatorial vertices, occurs in linear chains in Na29Zn24Sn32 (see picture; Sn blue). A pseudorotation of the {Sn14} enneahedron allows the number of covalent interactions within the complex three-dimensional atom arrangement to be adjusted, so that an electron-precise Zintl phase is attained.