The crystal structure of BiOCl

Abstract

Abstract The crystal structure of BiOCl has been redetermined with 3570 observed reflections of which 174 were unique measured on a computer controlled Philips PW 1100 single crystal diffractometer. The structure belongs to the tetragonal space group P4/nmm and the cell constants, obtained by a least-squares calculation from direct θ-value measurements on the diffractometer, are a = 3.8870(5) and c = 7.3540(5) Å. The positional and thermal parameters, with anisotropic temperature factors, were refined by full-matrix least-squares calculations to a final R = 9.17%. Each Bi atom is eight-coordinated by 4 O and 4 Cl atoms at distances of 2.316 Å and 3.059 Å respectively thus forming a decahedron. The faces of the decahedron are 2 rectangles (O–O–O–O and Cl–Cl–Cl–Cl) with sides 3.487 Å and 8 isosceles triangles (four O–Cl–O and four Cl–O–Cl) with sides O–Cl 3.249 Å and O–O or Cl–Cl 3.487 Å. The decahedra are linked to each other by a common O–Cl edge along the a and b axes in infinite layers.