Structure of the incommensurate composite crystal [Ba]x[(Pt,Cu)O3]

The nonstoichiometric compound [Ba] x [(Pt,Cu)O 3 ] (x=1.317) has a composite crystal structure with R P31c 111: P 1s R3m , a=5.817 (2), c=4.233 (1) A, k=(a * +b * )/3+1.519 (1)c * , V=124.0 A 3 , Z 1 =2, Z 2 =3, D x =7.46 Mg m -3 , Mo Kα, Cu Kβ, μ(Mo Kα)=42.9 mm -1 . The structure was analyzed by a newly developed computer program based on the theory reported in a previous paper [Yamamoto (1992). Acta Cryst. A48, 476-483]. Final R factors: 0.075 (overall), 0.041 (main), 0.108 (first-order satellite), 0.102 (second-order satellite) and 0.224 (third order satellite)