title: K-site splitting in KTiOPO4 at room temperature.
abstract: The room-temperature structure of potassium titanyl phosphate (KTiOPO4, KTP) with Pna2(1) symmetry has been studied by means of synchrotron radiation. Each of the two crystallographically unique K1 and K2 cations is split over two sites that are shifted along the c direction by 0.287 (13) and 0.255 (13) A for the K1a/b and K2a/b pairs, respectively. The refined populations of the minor K1b and K2b sites are 0.102 (12) and 0.132 (17), respectively. It is shown that accurate high-resolution synchrotron data (Rmerged = 0.015 for 25 010 reflections, 9456 unique, sintheta/lambda limit > 1.0) are required for the determination of a reliable structure model.
authors.affiliation: Ceramics Research Laboratory, Nagoya Institute of Technology, 10-6-29 Asahigaoka, Tajimi, Gifu 507-0071, Japan. stefan.norberg@gmail.com
authors.forename: Stefan T
authors.initials: ST
authors.lastname: Norberg
authors.forename: Nobuo
authors.initials: N
authors.lastname: Ishizawa