The crystal structure of BiTel

Abstract

Abstract The crystal structure of BiTeI has been redetermined with 1924 independent reflections, using three-dimensional intensities measured on a computer controlled Philips PW 1100 single crystal diffractometer. The structure belongs to the rhombohedral space group P3 and the cell constants, obtained by least-squares calculation from direct θ-value measurements on the diffractometer, are a = 4.336 and c = 6.84 Å and do not considerably deviate from those mentioned in the literature. The positional and thermal parameters, with anisotropic temperature factors, were refined by full-matrix least-squares calculations to a final R = 0.0745. Each Bi atom is six-coordinated by three Te and three I atoms at distances 3.88(5) Å and 3.05(2) Å respectively thus forming a distorted octahedron. The faces of the octahedron are two equilateral triangles (Te-Te-Te, I-I-I) with sides 4.336 Å and six isosceles triangles (three I-Te-I and three Te-I-Te) with sides I–Te 3.29(3) Å and I–I or Te–Te 4.336 Å. The octahedra are linked to each other by a common Te–I edge along the a and b axes in infinite layers.