title: Lutetium ultraphosphate.
abstract: The structure of the title compound, LuP(5)O(14), comprises puckered eight-membered PO(4) rings linked by the lutetium cations in a complex way, forming a three-dimensional framework. Each eight-membered phosphate ring shares a bridging tetra-hedron with each of four adjacent tetra-hedra, to form layers of PO(4) tetra-hedra. These layers are c/2 in thickness and parallel to the ab plane. Each Lu ion is contained in one such layer, forming bonds to six O atoms in that layer and also to one O atom belonging to a tetra-hedron in each of the layers lying above and below it. The LuO(8) polyhedra are isolated from one another, since they share no common atoms. The Lu ions lie on twofold axes (special position 4e) and the shortest Lu⋯Lu distance is 5.703 (1) Å.
authors.affiliation: Unité de Recherches de Matériaux de Terres Rares, Centre National de Recherches en Sciences des Matériaux, BP 95 Hammam-Lif, 2050, Tunisia.
authors.forename: Karima
authors.initials: K
authors.lastname: Horchani-Naifer
authors.forename: Mokhtar
authors.initials: M
authors.lastname: Férid