The crystal structure of the 1:1 CaO-Bi2O3 compound
(CaBi2O4) has been determined by single-crystal X-ray
and neutron powder diffraction techniques. The
compound crystallizes with the symmetry of the monoclinic
space group C2/c and lattice parameters
a=16.6130 ? , b=11.5900 ? , c=13.9939 ? , b=134.048°.The structure consists of sheets parallel to the b-c
plane and connected by Ca-O bonds. There is a structural
unit in each layer consisting of four Bi atoms, ten
oxygen atoms, and two calcium atoms. The Bi atoms
are fourfold coordinated and the coordination
polyhedron may be described as a short distorted
pyramid, open on one end to accommodate the lonepair
electrons of the bismuth atoms. Calcium is sevencoordinated
and the coordination polyhedron may be
described as a monocapped trigonal prism.
