The structure of the high-pressure cubic double perovskite Ca2TiSiO6 w
as refined using synchrotron X-ray powder data [S.G. <Fm(3)over bar m>
, a = 7.4105(1) Angstrom, Z = 4]. Ti and Si are fully ordered into alt
ernating octahedra in the perovskite framework, with Ca occupying a te
trahedrally distorted cuboctahedron. The cation-anion bond lengths are
Ti-O = 1.947(3) Angstrom, Si-O = 1.758(3) Angstrom, and Ca-O = 2.622(
1) degrees.