Redetermination of tricalcium trilanthanum pentakis(orthoborate) from single-crystal data

Single crystals of the title compound, Ca3La3(BO3)(5), were obtained by spontaneous nucleation from a high-temperature melt. The crystal structure of Ca3La3(BO3)(5) has been determined previously from X-ray powder data [Zhang, Liang, Chen, He & Xu (2001). J. Alloys Compd, 327, 96-99]. The present refinement shows a significant improvement in terms of the precision of the geometric parameters and the correct determination of the absolute configuration in space group P6(3)mc with all atoms refined with anisotropic displacement parameters. The structure consists of isolated BO3 triangles and distorted [CaO8] and [LaO10] polyhedra. Except for one O atom, all other atoms are situated on special positions: La, all O and one B atom on mirror planes, and two B atoms with site symmetry 3m.