SPACE GROUP AND LATTICE-CONSTANTS FOR BARIUM CERATE AND MINOR CORRECTIONS TO THE CRYSTAL-STRUCTURES OF BACE0.9Y0.1O2.95 AND BACE0.9GD0.1O2.95

The lattice constants and space group of undoped and lightly rare-eart h doped BaCeO3 have been investigated using high-resolution neutron po wder diffraction. The space group determined as Pmcn is unchanged from our earlier investigations; however, the lattice constants b and c ha ve had to be reversed to account for additional reflections observed i n the high-resolution diffraction pattern. The crystal structures of B aCe0.9Y0.1O2.95 and BaCe0.9Gd0.1O2.95 have been re-refined in the ligh t of this observation.