Ba3CoTa2O9 is (Cubic) Perovskite-derived structured and crystallizes in the trigonal P-3m1 space group. There are two inequivalent Ba sites. In the first Ba site, Ba(1) is bonded to six equivalent O(1) and six equivalent O(2) atoms to form BaO12 cuboctahedra that share corners with six equivalent Ba(1)O12 cuboctahedra, corners with six equivalent Ba(2)O12 cuboctahedra, faces with six equivalent Ba(2)O12 cuboctahedra, faces with two equivalent Co(1)O6 octahedra, and faces with six equivalent Ta(1)O6 octahedra. In the second Ba site, Ba(2) is bonded to three equivalent O(2) and nine equivalent O(1) atoms to form BaO12 cuboctahedra that share corners with three equivalent Ba(1)O12 cuboctahedra, corners with nine equivalent Ba(2)O12 cuboctahedra, faces with three equivalent Ba(1)O12 cuboctahedra, faces with three equivalent Ba(2)O12 cuboctahedra, faces with three equivalent Co(1)O6 octahedra, and faces with five equivalent Ta(1)O6 octahedra. Ta(1) is bonded to three equivalent O(1) and three equivalent O(2) atoms to form TaO6 octahedra that share corners with three equivalent Ta(1)O6 octahedra, corners with three equivalent Co(1)O6 octahedra, faces with three equivalent Ba(1)O12 cuboctahedra, and faces with five equivalent Ba(2)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-3°. Co(1) is bonded to six equivalent O(1) atoms to form CoO6 octahedra that share corners with six equivalent Ta(1)O6 octahedra, faces with two equivalent Ba(1)O12 cuboctahedra, and faces with six equivalent Ba(2)O12 cuboctahedra. The corner-sharing octahedral tilt angles are 3°. There are two inequivalent O sites. In the first O site, O(1) is bonded in a distorted linear geometry to one Ba(1), three equivalent Ba(2), one Ta(1), and one Co(1) atom. In the second O site, O(2) is bonded in a distorted linear geometry to two equivalent Ba(1), two equivalent Ba(2), and two equivalent Ta(1) atoms.
Ba3CoTa2O9 is (Cubic) Perovskite-derived structured and crystallizes in the trigonal P-3m1 space group. There are two inequivalent Ba sites. In the first Ba site, Ba(1) is bonded to six equivalent O(1) and six equivalent O(2) atoms to form BaO12 cuboctahedra that share corners with six equivalent Ba(1)O12 cuboctahedra, corners with six equivalent Ba(2)O12 cuboctahedra, faces with six equivalent Ba(2)O12 cuboctahedra, faces with two equivalent Co(1)O6 octahedra, and faces with six equivalent Ta(1)O6 octahedra. All Ba(1)-O(1) bond lengths are 2.87 Å. All Ba(1)-O(2) bond lengths are 2.88 Å. In the second Ba site, Ba(2) is bonded to three equivalent O(2) and nine equivalent O(1) atoms to form BaO12 cuboctahedra that share corners with three equivalent Ba(1)O12 cuboctahedra, corners with nine equivalent Ba(2)O12 cuboctahedra, faces with three equivalent Ba(1)O12 cuboctahedra, faces with three equivalent Ba(2)O12 cuboctahedra, faces with three equivalent Co(1)O6 octahedra, and faces with five equivalent Ta(1)O6 octahedra. All Ba(2)-O(2) bond lengths are 2.92 Å. There are three shorter (2.87 Å) and six longer (2.88 Å) Ba(2)-O(1) bond lengths. Ta(1) is bonded to three equivalent O(1) and three equivalent O(2) atoms to form TaO6 octahedra that share corners with three equivalent Ta(1)O6 octahedra, corners with three equivalent Co(1)O6 octahedra, faces with three equivalent Ba(1)O12 cuboctahedra, and faces with five equivalent Ba(2)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-3°. All Ta(1)-O(1) bond lengths are 1.94 Å. All Ta(1)-O(2) bond lengths are 2.08 Å. Co(1) is bonded to six equivalent O(1) atoms to form CoO6 octahedra that share corners with six equivalent Ta(1)O6 octahedra, faces with two equivalent Ba(1)O12 cuboctahedra, and faces with six equivalent Ba(2)O12 cuboctahedra. The corner-sharing octahedral tilt angles are 3°. All Co(1)-O(1) bond lengths are 2.09 Å. There are two inequivalent O sites. In the first O site, O(1) is bonded in a distorted linear geometry to one Ba(1), three equivalent Ba(2), one Ta(1), and one Co(1) atom. In the second O site, O(2) is bonded in a distorted linear geometry to two equivalent Ba(1), two equivalent Ba(2), and two equivalent Ta(1) atoms.