Ba6La2Co4O15 crystallizes in the monoclinic Cc space group. There are six inequivalent Ba sites. In the first Ba site, Ba(1) is bonded to two equivalent O(10), two equivalent O(11), and two equivalent O(12) atoms to form BaO6 octahedra that share corners with two equivalent Co(2)O4 tetrahedra, corners with two equivalent Co(3)O4 tetrahedra, corners with two equivalent Co(4)O4 tetrahedra, and faces with two equivalent Ba(1)O6 octahedra. In the second Ba site, Ba(2) is bonded to one O(1), one O(13), one O(14), one O(15), one O(2), one O(3), one O(4), one O(5), one O(6), one O(7), one O(8), and one O(9) atom to form distorted BaO12 cuboctahedra that share faces with two equivalent Co(1)O6 octahedra,  a faceface with one Co(2)O4 tetrahedra,  a faceface with one Co(3)O4 tetrahedra, and  a faceface with one Co(4)O4 tetrahedra. In the third Ba site, Ba(3) is bonded in a 8-coordinate geometry to one O(13), one O(15), one O(2), one O(3), one O(4), one O(6), one O(7), and one O(8) atom. In the fourth Ba site, Ba(4) is bonded in a 10-coordinate geometry to one O(1), one O(12), one O(14), one O(2), one O(7), one O(8), two equivalent O(11), and two equivalent O(5) atoms. In the fifth Ba site, Ba(5) is bonded in a 10-coordinate geometry to one O(1), one O(12), one O(15), one O(3), one O(4), one O(6), two equivalent O(10), and two equivalent O(9) atoms. In the sixth Ba site, Ba(6) is bonded in a 10-coordinate geometry to one O(10), one O(11), one O(12), one O(13), one O(2), one O(3), one O(4), one O(6), one O(7), and one O(8) atom. There are two inequivalent La sites. In the first La site, La(1) is bonded in a 8-coordinate geometry to one O(13), one O(14), one O(2), one O(3), one O(4), one O(6), one O(7), and one O(8) atom. In the second La site, La(2) is bonded in a 8-coordinate geometry to one O(14), one O(15), two equivalent O(1), two equivalent O(5), and two equivalent O(9) atoms. There are four inequivalent Co sites. In the first Co site, Co(1) is bonded to one O(1), one O(13), one O(14), one O(15), one O(2), and one O(3) atom to form CoO6 octahedra that share  a cornercorner with one Co(2)O4 tetrahedra,  a cornercorner with one Co(3)O4 tetrahedra,  a cornercorner with one Co(4)O4 tetrahedra, and faces with two equivalent Ba(2)O12 cuboctahedra. In the second Co site, Co(2) is bonded to one O(12), one O(13), one O(4), and one O(8) atom to form CoO4 tetrahedra that share  a cornercorner with one Co(1)O6 octahedra, corners with two equivalent Ba(1)O6 octahedra, and  a faceface with one Ba(2)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 10-68°. In the third Co site, Co(3) is bonded to one O(10), one O(15), one O(6), and one O(9) atom to form CoO4 tetrahedra that share  a cornercorner with one Co(1)O6 octahedra, corners with two equivalent Ba(1)O6 octahedra, and  a faceface with one Ba(2)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 10-68°. In the fourth Co site, Co(4) is bonded to one O(11), one O(14), one O(5), and one O(7) atom to form CoO4 tetrahedra that share  a cornercorner with one Co(1)O6 octahedra, corners with two equivalent Ba(1)O6 octahedra, and  a faceface with one Ba(2)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 5-65°. There are fifteen inequivalent O sites. In the first O site, O(1) is bonded to one Ba(2), one Ba(4), one Ba(5), two equivalent La(2), and one Co(1) atom to form distorted OBa3La2Co octahedra that share corners with two equivalent O(1)Ba3La2Co octahedra,  a faceface with one O(2)Ba4LaCo octahedra, and  a faceface with one O(3)Ba4LaCo octahedra. The corner-sharing octahedral tilt angles are 33°. In the second O site, O(2) is bonded to one Ba(2), one Ba(3), one Ba(4), one Ba(6), one La(1), and one Co(1) atom to form distorted OBa4LaCo octahedra that share corners with two equivalent O(3)Ba4LaCo octahedra,  a faceface with one O(1)Ba3La2Co octahedra, and  a faceface with one O(3)Ba4LaCo octahedra. The corner-sharing octahedral tilt angles range from 34-37°. In the third O site, O(3) is bonded to one Ba(2), one Ba(3), one Ba(5), one Ba(6), one La(1), and one Co(1) atom to form distorted OBa4LaCo octahedra that share corners with two equivalent O(2)Ba4LaCo octahedra,  a faceface with one O(1)Ba3La2Co octahedra, and  a faceface with one O(2)Ba4LaCo octahedra. The corner-sharing octahedral tilt angles range from 34-37°. In the fourth O site, O(4) is bonded in a 6-coordinate geometry to one Ba(2), one Ba(3), one Ba(5), one Ba(6), one La(1), and one Co(2) atom. In the fifth O site, O(5) is bonded in a 6-coordinate geometry to one Ba(2), two equivalent Ba(4), two equivalent La(2), and one Co(4) atom. In the sixth O site, O(6) is bonded in a 6-coordinate geometry to one Ba(2), one Ba(3), one Ba(5), one Ba(6), one La(1), and one Co(3) atom. In the seventh O site, O(7) is bonded in a 6-coordinate geometry to one Ba(2), one Ba(3), one Ba(4), one Ba(6), one La(1), and one Co(4) atom. In the eighth O site, O(8) is bonded in a 6-coordinate geometry to one Ba(2), one Ba(3), one Ba(4), one Ba(6), one La(1), and one Co(2) atom. In the ninth O site, O(9) is bonded in a 6-coordinate geometry to one Ba(2), two equivalent Ba(5), two equivalent La(2), and one Co(3) atom. In the tenth O site, O(10) is bonded in a 6-coordinate geometry to one Ba(6), two equivalent Ba(1), two equivalent Ba(5), and one Co(3) atom. In the eleventh O site, O(11) is bonded in a 6-coordinate geometry to one Ba(6), two equivalent Ba(1), two equivalent Ba(4), and one Co(4) atom. In the twelfth O site, O(12) is bonded in a 6-coordinate geometry to one Ba(4), one Ba(5), one Ba(6), two equivalent Ba(1), and one Co(2) atom. In the thirteenth O site, O(13) is bonded in a 6-coordinate geometry to one Ba(2), one Ba(3), one Ba(6), one La(1), one Co(1), and one Co(2) atom. In the fourteenth O site, O(14) is bonded in a 6-coordinate geometry to one Ba(2), one Ba(4), one La(1), one La(2), one Co(1), and one Co(4) atom. In the fifteenth O site, O(15) is bonded in a 6-coordinate geometry to one Ba(2), one Ba(3), one Ba(5), one La(2), one Co(1), and one Co(3) atom.
Ba6La2Co4O15 crystallizes in the monoclinic Cc space group. There are six inequivalent Ba sites. In the first Ba site, Ba(1) is bonded to two equivalent O(10), two equivalent O(11), and two equivalent O(12) atoms to form BaO6 octahedra that share corners with two equivalent Co(2)O4 tetrahedra, corners with two equivalent Co(3)O4 tetrahedra, corners with two equivalent Co(4)O4 tetrahedra, and faces with two equivalent Ba(1)O6 octahedra. There is one shorter (2.67 Å) and one longer (2.76 Å) Ba(1)-O(10) bond length. There is one shorter (2.57 Å) and one longer (2.73 Å) Ba(1)-O(11) bond length. There is one shorter (2.60 Å) and one longer (2.76 Å) Ba(1)-O(12) bond length. In the second Ba site, Ba(2) is bonded to one O(1), one O(13), one O(14), one O(15), one O(2), one O(3), one O(4), one O(5), one O(6), one O(7), one O(8), and one O(9) atom to form distorted BaO12 cuboctahedra that share faces with two equivalent Co(1)O6 octahedra,  a faceface with one Co(2)O4 tetrahedra,  a faceface with one Co(3)O4 tetrahedra, and  a faceface with one Co(4)O4 tetrahedra. The Ba(2)-O(1) bond length is 2.78 Å. The Ba(2)-O(13) bond length is 3.13 Å. The Ba(2)-O(14) bond length is 3.11 Å. The Ba(2)-O(15) bond length is 3.14 Å. The Ba(2)-O(2) bond length is 2.82 Å. The Ba(2)-O(3) bond length is 2.72 Å. The Ba(2)-O(4) bond length is 3.23 Å. The Ba(2)-O(5) bond length is 3.24 Å. The Ba(2)-O(6) bond length is 3.24 Å. The Ba(2)-O(7) bond length is 3.24 Å. The Ba(2)-O(8) bond length is 3.27 Å. The Ba(2)-O(9) bond length is 3.18 Å. In the third Ba site, Ba(3) is bonded in a 8-coordinate geometry to one O(13), one O(15), one O(2), one O(3), one O(4), one O(6), one O(7), and one O(8) atom. The Ba(3)-O(13) bond length is 2.71 Å. The Ba(3)-O(15) bond length is 2.69 Å. The Ba(3)-O(2) bond length is 2.67 Å. The Ba(3)-O(3) bond length is 2.77 Å. The Ba(3)-O(4) bond length is 2.59 Å. The Ba(3)-O(6) bond length is 2.81 Å. The Ba(3)-O(7) bond length is 2.59 Å. The Ba(3)-O(8) bond length is 2.85 Å. In the fourth Ba site, Ba(4) is bonded in a 10-coordinate geometry to one O(1), one O(12), one O(14), one O(2), one O(7), one O(8), two equivalent O(11), and two equivalent O(5) atoms. The Ba(4)-O(1) bond length is 2.79 Å. The Ba(4)-O(12) bond length is 3.30 Å. The Ba(4)-O(14) bond length is 2.73 Å. The Ba(4)-O(2) bond length is 2.81 Å. The Ba(4)-O(7) bond length is 3.11 Å. The Ba(4)-O(8) bond length is 3.00 Å. There is one shorter (3.12 Å) and one longer (3.40 Å) Ba(4)-O(11) bond length. There is one shorter (2.84 Å) and one longer (3.12 Å) Ba(4)-O(5) bond length. In the fifth Ba site, Ba(5) is bonded in a 10-coordinate geometry to one O(1), one O(12), one O(15), one O(3), one O(4), one O(6), two equivalent O(10), and two equivalent O(9) atoms. The Ba(5)-O(1) bond length is 2.84 Å. The Ba(5)-O(12) bond length is 3.28 Å. The Ba(5)-O(15) bond length is 2.79 Å. The Ba(5)-O(3) bond length is 2.80 Å. The Ba(5)-O(4) bond length is 2.93 Å. The Ba(5)-O(6) bond length is 2.95 Å. There is one shorter (3.21 Å) and one longer (3.25 Å) Ba(5)-O(10) bond length. There is one shorter (2.96 Å) and one longer (3.09 Å) Ba(5)-O(9) bond length. In the sixth Ba site, Ba(6) is bonded in a 10-coordinate geometry to one O(10), one O(11), one O(12), one O(13), one O(2), one O(3), one O(4), one O(6), one O(7), and one O(8) atom. The Ba(6)-O(10) bond length is 3.33 Å. The Ba(6)-O(11) bond length is 3.35 Å. The Ba(6)-O(12) bond length is 3.31 Å. The Ba(6)-O(13) bond length is 2.76 Å. The Ba(6)-O(2) bond length is 2.80 Å. The Ba(6)-O(3) bond length is 2.77 Å. The Ba(6)-O(4) bond length is 3.11 Å. The Ba(6)-O(6) bond length is 3.06 Å. The Ba(6)-O(7) bond length is 2.92 Å. The Ba(6)-O(8) bond length is 2.97 Å. There are two inequivalent La sites. In the first La site, La(1) is bonded in a 8-coordinate geometry to one O(13), one O(14), one O(2), one O(3), one O(4), one O(6), one O(7), and one O(8) atom. The La(1)-O(13) bond length is 2.48 Å. The La(1)-O(14) bond length is 2.62 Å. The La(1)-O(2) bond length is 2.76 Å. The La(1)-O(3) bond length is 2.45 Å. The La(1)-O(4) bond length is 2.58 Å. The La(1)-O(6) bond length is 2.51 Å. The La(1)-O(7) bond length is 2.65 Å. The La(1)-O(8) bond length is 2.48 Å. In the second La site, La(2) is bonded in a 8-coordinate geometry to one O(14), one O(15), two equivalent O(1), two equivalent O(5), and two equivalent O(9) atoms. The La(2)-O(14) bond length is 2.56 Å. The La(2)-O(15) bond length is 2.46 Å. There is one shorter (2.54 Å) and one longer (2.69 Å) La(2)-O(1) bond length. There is one shorter (2.39 Å) and one longer (2.71 Å) La(2)-O(5) bond length. There is one shorter (2.45 Å) and one longer (2.67 Å) La(2)-O(9) bond length. There are four inequivalent Co sites. In the first Co site, Co(1) is bonded to one O(1), one O(13), one O(14), one O(15), one O(2), and one O(3) atom to form CoO6 octahedra that share  a cornercorner with one Co(2)O4 tetrahedra,  a cornercorner with one Co(3)O4 tetrahedra,  a cornercorner with one Co(4)O4 tetrahedra, and faces with two equivalent Ba(2)O12 cuboctahedra. The Co(1)-O(1) bond length is 1.98 Å. The Co(1)-O(13) bond length is 2.12 Å. The Co(1)-O(14) bond length is 2.27 Å. The Co(1)-O(15) bond length is 2.06 Å. The Co(1)-O(2) bond length is 1.88 Å. The Co(1)-O(3) bond length is 2.11 Å. In the second Co site, Co(2) is bonded to one O(12), one O(13), one O(4), and one O(8) atom to form CoO4 tetrahedra that share  a cornercorner with one Co(1)O6 octahedra, corners with two equivalent Ba(1)O6 octahedra, and  a faceface with one Ba(2)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 10-68°. The Co(2)-O(12) bond length is 1.80 Å. The Co(2)-O(13) bond length is 1.99 Å. The Co(2)-O(4) bond length is 1.90 Å. The Co(2)-O(8) bond length is 1.82 Å. In the third Co site, Co(3) is bonded to one O(10), one O(15), one O(6), and one O(9) atom to form CoO4 tetrahedra that share  a cornercorner with one Co(1)O6 octahedra, corners with two equivalent Ba(1)O6 octahedra, and  a faceface with one Ba(2)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 10-68°. The Co(3)-O(10) bond length is 1.80 Å. The Co(3)-O(15) bond length is 2.01 Å. The Co(3)-O(6) bond length is 1.82 Å. The Co(3)-O(9) bond length is 1.93 Å. In the fourth Co site, Co(4) is bonded to one O(11), one O(14), one O(5), and one O(7) atom to form CoO4 tetrahedra that share  a cornercorner with one Co(1)O6 octahedra, corners with two equivalent Ba(1)O6 octahedra, and  a faceface with one Ba(2)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 5-65°. The Co(4)-O(11) bond length is 1.81 Å. The Co(4)-O(14) bond length is 1.92 Å. The Co(4)-O(5) bond length is 1.92 Å. The Co(4)-O(7) bond length is 1.81 Å. There are fifteen inequivalent O sites. In the first O site, O(1) is bonded to one Ba(2), one Ba(4), one Ba(5), two equivalent La(2), and one Co(1) atom to form distorted OBa3La2Co octahedra that share corners with two equivalent O(1)Ba3La2Co octahedra,  a faceface with one O(2)Ba4LaCo octahedra, and  a faceface with one O(3)Ba4LaCo octahedra. The corner-sharing octahedral tilt angles are 33°. In the second O site, O(2) is bonded to one Ba(2), one Ba(3), one Ba(4), one Ba(6), one La(1), and one Co(1) atom to form distorted OBa4LaCo octahedra that share corners with two equivalent O(3)Ba4LaCo octahedra,  a faceface with one O(1)Ba3La2Co octahedra, and  a faceface with one O(3)Ba4LaCo octahedra. The corner-sharing octahedral tilt angles range from 34-37°. In the third O site, O(3) is bonded to one Ba(2), one Ba(3), one Ba(5), one Ba(6), one La(1), and one Co(1) atom to form distorted OBa4LaCo octahedra that share corners with two equivalent O(2)Ba4LaCo octahedra,  a faceface with one O(1)Ba3La2Co octahedra, and  a faceface with one O(2)Ba4LaCo octahedra. The corner-sharing octahedral tilt angles range from 34-37°. In the fourth O site, O(4) is bonded in a 6-coordinate geometry to one Ba(2), one Ba(3), one Ba(5), one Ba(6), one La(1), and one Co(2) atom. In the fifth O site, O(5) is bonded in a 6-coordinate geometry to one Ba(2), two equivalent Ba(4), two equivalent La(2), and one Co(4) atom. In the sixth O site, O(6) is bonded in a 6-coordinate geometry to one Ba(2), one Ba(3), one Ba(5), one Ba(6), one La(1), and one Co(3) atom. In the seventh O site, O(7) is bonded in a 6-coordinate geometry to one Ba(2), one Ba(3), one Ba(4), one Ba(6), one La(1), and one Co(4) atom. In the eighth O site, O(8) is bonded in a 6-coordinate geometry to one Ba(2), one Ba(3), one Ba(4), one Ba(6), one La(1), and one Co(2) atom. In the ninth O site, O(9) is bonded in a 6-coordinate geometry to one Ba(2), two equivalent Ba(5), two equivalent La(2), and one Co(3) atom. In the tenth O site, O(10) is bonded in a 6-coordinate geometry to one Ba(6), two equivalent Ba(1), two equivalent Ba(5), and one Co(3) atom. In the eleventh O site, O(11) is bonded in a 6-coordinate geometry to one Ba(6), two equivalent Ba(1), two equivalent Ba(4), and one Co(4) atom. In the twelfth O site, O(12) is bonded in a 6-coordinate geometry to one Ba(4), one Ba(5), one Ba(6), two equivalent Ba(1), and one Co(2) atom. In the thirteenth O site, O(13) is bonded in a 6-coordinate geometry to one Ba(2), one Ba(3), one Ba(6), one La(1), one Co(1), and one Co(2) atom. In the fourteenth O site, O(14) is bonded in a 6-coordinate geometry to one Ba(2), one Ba(4), one La(1), one La(2), one Co(1), and one Co(4) atom. In the fifteenth O site, O(15) is bonded in a 6-coordinate geometry to one Ba(2), one Ba(3), one Ba(5), one La(2), one Co(1), and one Co(3) atom.