title: The complex phosphate K0.92In0.46Nb0.54OPO4: a new representative of the KTiOPO4 family.
abstract: Aliovalent K(0.92)In(0.46)Nb(0.54)OPO(4) (KINP, potassium indium niobium oxide phosphate) features a chain structure involving corner-sharing [MO(6)] octahedra (M = In/Nb), which allows this compound to be recognized as a member of the KTiOPO(4) (KTP) family. However, its crystallization in the polar space group P4(1) belonging to the 4/m Laue group generates its own subclass of KTP-related compounds. The unit cell contains 18 symmetry-independent atoms occupying general positions. The cis-cis principle of octahedral arrangement is observed for each of the separate [MO(6)](infinity) chains. The observed variations in the cis-cis linkage are critically important for nonlinear optical properties and distinguish the present compound from other KTP-related structures. The anionic framework adopts one-dimensional tunnels running orthogonal to the ab plane. The K(+) ions are arranged in the [001] direction at a distance of 1/4c. Merohedral twinning was detected during the structure refinement.
authors.affiliation: Department of Inorganic Chemistry, Taras Shevchenko National University, 64 Volodymyrska Street, 01033 Kyiv, Ukraine. babaryk@bigmir.net
authors.forename: Artem A
authors.initials: AA
authors.lastname: Babaryk
authors.forename: Igor V
authors.initials: IV
authors.lastname: Zatovsky
authors.forename: Vyacheslav N
authors.initials: VN
authors.lastname: Baumer
authors.forename: Nikolay S
authors.initials: NS
authors.lastname: Slobodyanik
authors.forename: Konstantin V
authors.initials: KV
authors.lastname: Domasevitch