title: K(0.12)Na(0.54)Ag(0.34)Nb(4)O(9)AsO(4).
abstract: Potassium sodium silver tetra-niobium nona-oxide arsenate, K(0.12)Na(0.54)Ag(0.34)Nb(4)AsO(13), synthesized by solid-state reaction at 1123 K, adopts a three-dimensional framework delimiting tunnels running along [001] in which occupationally disordered sodium, silver, and potassium ions are located. Of the 11 atoms in the asymmetric unit (two Nb, one As, one Ag, one K, one Na and fiveO), nine are located on special positions: one Nb and the K, Ag, Na and two O atoms are situated on mirror planes, the other Nb is on a twofold rotation axis, and the As atom and one O atom are on sites of m2m symmetry.
authors.affiliation: Laboratoire de Matériaux et Cristallochimie, Faculté des Sciences de Tunis, Université de Tunis El Manar, 2092 Manar II Tunis, Tunisia.
authors.forename: Saïda Fatma
authors.initials: SF
authors.lastname: Chérif
authors.forename: Mohamed Faouzi
authors.initials: MF
authors.lastname: Zid
authors.forename: Ahmed
authors.initials: A
authors.lastname: Driss