CrAl19O30 is Ilmenite-like structured and crystallizes in the triclinic P1 space group. Cr(1) is bonded to one O(10), one O(17), one O(2), one O(22), one O(4), and one O(8) atom to form CrO6 octahedra that share  a cornercorner with one Al(11)O6 octahedra, corners with two equivalent Al(1)O6 octahedra, corners with three equivalent Al(16)O6 octahedra, corners with three equivalent Al(9)O6 octahedra,  an edgeedge with one Al(4)O6 octahedra, edges with two equivalent Al(19)O6 octahedra, and  a faceface with one Al(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 49-63°. There are nineteen inequivalent Al sites. In the first Al site, Al(1) is bonded to one O(10), one O(17), one O(2), one O(4), one O(6), and one O(8) atom to form AlO6 octahedra that share  a cornercorner with one Al(2)O6 octahedra, corners with two equivalent Cr(1)O6 octahedra, corners with three equivalent Al(19)O6 octahedra, corners with three equivalent Al(4)O6 octahedra,  an edgeedge with one Al(16)O6 octahedra, edges with two equivalent Al(9)O6 octahedra, and  a faceface with one Cr(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 44-63°. In the second Al site, Al(2) is bonded to one O(11), one O(14), one O(20), one O(25), one O(3), and one O(6) atom to form a mixture of edge, face, and corner-sharing AlO6 octahedra. The corner-sharing octahedral tilt angles range from 48-60°. In the third Al site, Al(3) is bonded to one O(1), one O(12), one O(14), one O(23), one O(3), and one O(5) atom to form a mixture of edge, face, and corner-sharing AlO6 octahedra. The corner-sharing octahedral tilt angles range from 48-60°. In the fourth Al site, Al(4) is bonded to one O(11), one O(2), one O(20), one O(25), one O(4), and one O(6) atom to form AlO6 octahedra that share  a cornercorner with one Al(14)O6 octahedra, corners with two equivalent Al(9)O6 octahedra, corners with three equivalent Al(1)O6 octahedra, corners with three equivalent Al(8)O6 octahedra,  an edgeedge with one Cr(1)O6 octahedra, edges with two equivalent Al(2)O6 octahedra, and  a faceface with one Al(9)O6 octahedra. The corner-sharing octahedral tilt angles range from 45-60°. In the fifth Al site, Al(5) is bonded to one O(1), one O(15), one O(16), one O(19), one O(26), and one O(30) atom to form a mixture of edge, face, and corner-sharing AlO6 octahedra. The corner-sharing octahedral tilt angles range from 48-60°. In the sixth Al site, Al(6) is bonded to one O(18), one O(19), one O(26), one O(27), one O(7), and one O(9) atom to form a mixture of edge, face, and corner-sharing AlO6 octahedra. The corner-sharing octahedral tilt angles range from 48-60°. In the seventh Al site, Al(7) is bonded to one O(1), one O(12), one O(15), one O(16), one O(23), and one O(5) atom to form a mixture of edge, face, and corner-sharing AlO6 octahedra. The corner-sharing octahedral tilt angles range from 48-60°. In the eighth Al site, Al(8) is bonded to one O(11), one O(14), one O(20), one O(23), one O(25), and one O(3) atom to form a mixture of edge, face, and corner-sharing AlO6 octahedra. The corner-sharing octahedral tilt angles range from 47-60°. In the ninth Al site, Al(9) is bonded to one O(11), one O(2), one O(20), one O(4), one O(6), and one O(8) atom to form AlO6 octahedra that share  a cornercorner with one Al(19)O6 octahedra, corners with two equivalent Al(4)O6 octahedra, corners with three equivalent Cr(1)O6 octahedra, corners with three equivalent Al(2)O6 octahedra,  an edgeedge with one Al(8)O6 octahedra, edges with two equivalent Al(1)O6 octahedra, and  a faceface with one Al(4)O6 octahedra. The corner-sharing octahedral tilt angles range from 48-59°. In the tenth Al site, Al(10) is bonded to one O(15), one O(16), one O(19), one O(26), one O(30), and one O(9) atom to form a mixture of edge, face, and corner-sharing AlO6 octahedra. The corner-sharing octahedral tilt angles range from 48-60°. In the eleventh Al site, Al(11) is bonded to one O(13), one O(21), one O(22), one O(24), one O(28), and one O(29) atom to form AlO6 octahedra that share  a cornercorner with one Cr(1)O6 octahedra, corners with two equivalent Al(13)O6 octahedra, corners with three equivalent Al(18)O6 octahedra, corners with three equivalent Al(19)O6 octahedra,  an edgeedge with one Al(12)O6 octahedra, edges with two equivalent Al(16)O6 octahedra, and  a faceface with one Al(13)O6 octahedra. The corner-sharing octahedral tilt angles range from 45-61°. In the twelfth Al site, Al(12) is bonded to one O(13), one O(18), one O(21), one O(27), one O(7), and one O(9) atom to form a mixture of edge, face, and corner-sharing AlO6 octahedra. The corner-sharing octahedral tilt angles range from 47-60°. In the thirteenth Al site, Al(13) is bonded to one O(13), one O(21), one O(24), one O(28), one O(29), and one O(7) atom to form a mixture of edge, face, and corner-sharing AlO6 octahedra. The corner-sharing octahedral tilt angles range from 47-60°. In the fourteenth Al site, Al(14) is bonded to one O(12), one O(14), one O(23), one O(25), one O(3), and one O(5) atom to form a mixture of edge, face, and corner-sharing AlO6 octahedra. The corner-sharing octahedral tilt angles range from 48-60°. In the fifteenth Al site, Al(15) is bonded to one O(18), one O(19), one O(26), one O(27), one O(30), and one O(9) atom to form a mixture of edge, face, and corner-sharing AlO6 octahedra. The corner-sharing octahedral tilt angles range from 48-60°. In the sixteenth Al site, Al(16) is bonded to one O(10), one O(17), one O(22), one O(24), one O(28), and one O(29) atom to form AlO6 octahedra that share  a cornercorner with one Al(18)O6 octahedra, corners with two equivalent Al(19)O6 octahedra, corners with three equivalent Cr(1)O6 octahedra, corners with three equivalent Al(13)O6 octahedra,  an edgeedge with one Al(1)O6 octahedra, edges with two equivalent Al(11)O6 octahedra, and  a faceface with one Al(19)O6 octahedra. The corner-sharing octahedral tilt angles range from 48-60°. In the seventeenth Al site, Al(17) is bonded to one O(1), one O(12), one O(15), one O(16), one O(30), and one O(5) atom to form a mixture of edge, face, and corner-sharing AlO6 octahedra. The corner-sharing octahedral tilt angles range from 48-60°. In the eighteenth Al site, Al(18) is bonded to one O(13), one O(18), one O(21), one O(24), one O(27), and one O(7) atom to form a mixture of edge, face, and corner-sharing AlO6 octahedra. The corner-sharing octahedral tilt angles range from 47-60°. In the nineteenth Al site, Al(19) is bonded to one O(10), one O(17), one O(22), one O(28), one O(29), and one O(8) atom to form AlO6 octahedra that share  a cornercorner with one Al(9)O6 octahedra, corners with two equivalent Al(16)O6 octahedra, corners with three equivalent Al(1)O6 octahedra, corners with three equivalent Al(11)O6 octahedra,  an edgeedge with one Al(13)O6 octahedra, edges with two equivalent Cr(1)O6 octahedra, and  a faceface with one Al(16)O6 octahedra. The corner-sharing octahedral tilt angles range from 44-59°. There are thirty inequivalent O sites. In the first O site, O(1) is bonded to one Al(17), one Al(3), one Al(5), and one Al(7) atom to form a mixture of distorted edge and corner-sharing OAl4 trigonal pyramids. In the second O site, O(2) is bonded to one Cr(1), one Al(1), one Al(4), and one Al(9) atom to form distorted OAl3Cr trigonal pyramids that share  a cornercorner with one O(8)Al3Cr trigonal pyramid,  a cornercorner with one O(25)Al4 trigonal pyramid, corners with two equivalent O(11)Al4 trigonal pyramids, corners with two equivalent O(20)Al4 trigonal pyramids, corners with three equivalent O(6)Al4 trigonal pyramids,  an edgeedge with one O(10)Al3Cr trigonal pyramid, and  an edgeedge with one O(8)Al3Cr trigonal pyramid. In the third O site, O(3) is bonded to one Al(14), one Al(2), one Al(3), and one Al(8) atom to form a mixture of distorted edge and corner-sharing OAl4 trigonal pyramids. In the fourth O site, O(4) is bonded in a distorted see-saw-like geometry to one Cr(1), one Al(1), one Al(4), and one Al(9) atom. In the fifth O site, O(5) is bonded to one Al(14), one Al(17), one Al(3), and one Al(7) atom to form a mixture of distorted edge and corner-sharing OAl4 trigonal pyramids. In the sixth O site, O(6) is bonded to one Al(1), one Al(2), one Al(4), and one Al(9) atom to form distorted OAl4 trigonal pyramids that share  a cornercorner with one O(10)Al3Cr trigonal pyramid,  a cornercorner with one O(14)Al4 trigonal pyramid,  a cornercorner with one O(20)Al4 trigonal pyramid,  a cornercorner with one O(3)Al4 trigonal pyramid, corners with three equivalent O(2)Al3Cr trigonal pyramids, corners with three equivalent O(11)Al4 trigonal pyramids,  an edgeedge with one O(8)Al3Cr trigonal pyramid,  an edgeedge with one O(20)Al4 trigonal pyramid, and  an edgeedge with one O(25)Al4 trigonal pyramid. In the seventh O site, O(7) is bonded to one Al(12), one Al(13), one Al(18), and one Al(6) atom to form a mixture of distorted edge and corner-sharing OAl4 trigonal pyramids. In the eighth O site, O(8) is bonded to one Cr(1), one Al(1), one Al(19), and one Al(9) atom to form distorted OAl3Cr trigonal pyramids that share  a cornercorner with one O(10)Al3Cr trigonal pyramid,  a cornercorner with one O(2)Al3Cr trigonal pyramid,  a cornercorner with one O(11)Al4 trigonal pyramid,  a cornercorner with one O(20)Al4 trigonal pyramid,  a cornercorner with one O(28)Al4 trigonal pyramid,  a cornercorner with one O(29)Al4 trigonal pyramid,  an edgeedge with one O(10)Al3Cr trigonal pyramid,  an edgeedge with one O(2)Al3Cr trigonal pyramid, and  an edgeedge with one O(6)Al4 trigonal pyramid. In the ninth O site, O(9) is bonded to one Al(10), one Al(12), one Al(15), and one Al(6) atom to form a mixture of distorted edge and corner-sharing OAl4 trigonal pyramids. In the tenth O site, O(10) is bonded to one Cr(1), one Al(1), one Al(16), and one Al(19) atom to form distorted OAl3Cr trigonal pyramids that share  a cornercorner with one O(8)Al3Cr trigonal pyramid,  a cornercorner with one O(24)Al4 trigonal pyramid,  a cornercorner with one O(6)Al4 trigonal pyramid, corners with two equivalent O(28)Al4 trigonal pyramids, corners with two equivalent O(29)Al4 trigonal pyramids,  an edgeedge with one O(2)Al3Cr trigonal pyramid, and  an edgeedge with one O(8)Al3Cr trigonal pyramid. In the eleventh O site, O(11) is bonded to one Al(2), one Al(4), one Al(8), and one Al(9) atom to form distorted OAl4 trigonal pyramids that share  a cornercorner with one O(8)Al3Cr trigonal pyramid,  a cornercorner with one O(23)Al4 trigonal pyramid,  a cornercorner with one O(25)Al4 trigonal pyramid, corners with two equivalent O(2)Al3Cr trigonal pyramids, corners with two equivalent O(3)Al4 trigonal pyramids, corners with three equivalent O(6)Al4 trigonal pyramids,  an edgeedge with one O(14)Al4 trigonal pyramid,  an edgeedge with one O(25)Al4 trigonal pyramid, and edges with two equivalent O(20)Al4 trigonal pyramids. In the twelfth O site, O(12) is bonded to one Al(14), one Al(17), one Al(3), and one Al(7) atom to form a mixture of distorted edge and corner-sharing OAl4 trigonal pyramids. In the thirteenth O site, O(13) is bonded to one Al(11), one Al(12), one Al(13), and one Al(18) atom to form a mixture of distorted edge and corner-sharing OAl4 trigonal pyramids. In the fourteenth O site, O(14) is bonded to one Al(14), one Al(2), one Al(3), and one Al(8) atom to form a mixture of distorted edge and corner-sharing OAl4 trigonal pyramids. In the fifteenth O site, O(15) is bonded to one Al(10), one Al(17), one Al(5), and one Al(7) atom to form a mixture of distorted edge and corner-sharing OAl4 trigonal pyramids. In the sixteenth O site, O(16) is bonded to one Al(10), one Al(17), one Al(5), and one Al(7) atom to form a mixture of distorted edge and corner-sharing OAl4 trigonal pyramids. In the seventeenth O site, O(17) is bonded in a distorted see-saw-like geometry to one Cr(1), one Al(1), one Al(16), and one Al(19) atom. In the eighteenth O site, O(18) is bonded to one Al(12), one Al(15), one Al(18), and one Al(6) atom to form a mixture of distorted edge and corner-sharing OAl4 trigonal pyramids. In the nineteenth O site, O(19) is bonded to one Al(10), one Al(15), one Al(5), and one Al(6) atom to form a mixture of distorted edge and corner-sharing OAl4 trigonal pyramids. In the twentieth O site, O(20) is bonded to one Al(2), one Al(4), one Al(8), and one Al(9) atom to form distorted OAl4 trigonal pyramids that share  a cornercorner with one O(8)Al3Cr trigonal pyramid,  a cornercorner with one O(23)Al4 trigonal pyramid,  a cornercorner with one O(6)Al4 trigonal pyramid, corners with two equivalent O(2)Al3Cr trigonal pyramids, corners with two equivalent O(14)Al4 trigonal pyramids, corners with two equivalent O(3)Al4 trigonal pyramids, corners with three equivalent O(25)Al4 trigonal pyramids,  an edgeedge with one O(6)Al4 trigonal pyramid, and edges with two equivalent O(11)Al4 trigonal pyramids. In the twenty-first O site, O(21) is bonded to one Al(11), one Al(12), one Al(13), and one Al(18) atom to form a mixture of distorted edge and corner-sharing OAl4 trigonal pyramids. In the twenty-second O site, O(22) is bonded in a rectangular see-saw-like geometry to one Cr(1), one Al(11), one Al(16), and one Al(19) atom. In the twenty-third O site, O(23) is bonded to one Al(14), one Al(3), one Al(7), and one Al(8) atom to form a mixture of distorted edge and corner-sharing OAl4 trigonal pyramids. In the twenty-fourth O site, O(24) is bonded to one Al(11), one Al(13), one Al(16), and one Al(18) atom to form distorted OAl4 trigonal pyramids that share  a cornercorner with one O(10)Al3Cr trigonal pyramid,  a cornercorner with one O(13)Al4 trigonal pyramid,  a cornercorner with one O(18)Al4 trigonal pyramid,  a cornercorner with one O(27)Al4 trigonal pyramid,  a cornercorner with one O(28)Al4 trigonal pyramid, corners with three equivalent O(21)Al4 trigonal pyramids, corners with three equivalent O(29)Al4 trigonal pyramids,  an edgeedge with one O(13)Al4 trigonal pyramid,  an edgeedge with one O(28)Al4 trigonal pyramid, and  an edgeedge with one O(7)Al4 trigonal pyramid. In the twenty-fifth O site, O(25) is bonded to one Al(14), one Al(2), one Al(4), and one Al(8) atom to form distorted OAl4 trigonal pyramids that share  a cornercorner with one O(2)Al3Cr trigonal pyramid,  a cornercorner with one O(11)Al4 trigonal pyramid,  a cornercorner with one O(12)Al4 trigonal pyramid,  a cornercorner with one O(14)Al4 trigonal pyramid,  a cornercorner with one O(5)Al4 trigonal pyramid, corners with three equivalent O(20)Al4 trigonal pyramids, corners with three equivalent O(3)Al4 trigonal pyramids,  an edgeedge with one O(11)Al4 trigonal pyramid,  an edgeedge with one O(14)Al4 trigonal pyramid,  an edgeedge with one O(23)Al4 trigonal pyramid, and  an edgeedge with one O(6)Al4 trigonal pyramid. In the twenty-sixth O site, O(26) is bonded to one Al(10), one Al(15), one Al(5), and one Al(6) atom to form a mixture of distorted edge and corner-sharing OAl4 trigonal pyramids. In the twenty-seventh O site, O(27) is bonded to one Al(12), one Al(15), one Al(18), and one Al(6) atom to form a mixture of distorted edge and corner-sharing OAl4 trigonal pyramids. In the twenty-eighth O site, O(28) is bonded to one Al(11), one Al(13), one Al(16), and one Al(19) atom to form distorted OAl4 trigonal pyramids that share  a cornercorner with one O(8)Al3Cr trigonal pyramid,  a cornercorner with one O(24)Al4 trigonal pyramid,  a cornercorner with one O(7)Al4 trigonal pyramid, corners with two equivalent O(10)Al3Cr trigonal pyramids, corners with two equivalent O(21)Al4 trigonal pyramids,  an edgeedge with one O(13)Al4 trigonal pyramid,  an edgeedge with one O(24)Al4 trigonal pyramid, and edges with two equivalent O(29)Al4 trigonal pyramids. In the twenty-ninth O site, O(29) is bonded to one Al(11), one Al(13), one Al(16), and one Al(19) atom to form distorted OAl4 trigonal pyramids that share  a cornercorner with one O(8)Al3Cr trigonal pyramid,  a cornercorner with one O(7)Al4 trigonal pyramid, corners with two equivalent O(10)Al3Cr trigonal pyramids, corners with two equivalent O(13)Al4 trigonal pyramids, corners with two equivalent O(21)Al4 trigonal pyramids, corners with three equivalent O(24)Al4 trigonal pyramids, and edges with two equivalent O(28)Al4 trigonal pyramids. In the thirtieth O site, O(30) is bonded to one Al(10), one Al(15), one Al(17), and one Al(5) atom to form a mixture of distorted edge and corner-sharing OAl4 trigonal pyramids.
CrAl19O30 is Ilmenite-like structured and crystallizes in the triclinic P1 space group. Cr(1) is bonded to one O(10), one O(17), one O(2), one O(22), one O(4), and one O(8) atom to form CrO6 octahedra that share  a cornercorner with one Al(11)O6 octahedra, corners with two equivalent Al(1)O6 octahedra, corners with three equivalent Al(16)O6 octahedra, corners with three equivalent Al(9)O6 octahedra,  an edgeedge with one Al(4)O6 octahedra, edges with two equivalent Al(19)O6 octahedra, and  a faceface with one Al(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 49-63°. The Cr(1)-O(10) bond length is 2.02 Å. The Cr(1)-O(17) bond length is 1.97 Å. The Cr(1)-O(2) bond length is 2.03 Å. The Cr(1)-O(22) bond length is 1.97 Å. The Cr(1)-O(4) bond length is 1.98 Å. The Cr(1)-O(8) bond length is 2.03 Å. There are nineteen inequivalent Al sites. In the first Al site, Al(1) is bonded to one O(10), one O(17), one O(2), one O(4), one O(6), and one O(8) atom to form AlO6 octahedra that share  a cornercorner with one Al(2)O6 octahedra, corners with two equivalent Cr(1)O6 octahedra, corners with three equivalent Al(19)O6 octahedra, corners with three equivalent Al(4)O6 octahedra,  an edgeedge with one Al(16)O6 octahedra, edges with two equivalent Al(9)O6 octahedra, and  a faceface with one Cr(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 44-63°. The Al(1)-O(10) bond length is 2.02 Å. The Al(1)-O(17) bond length is 1.85 Å. The Al(1)-O(2) bond length is 2.01 Å. The Al(1)-O(4) bond length is 1.85 Å. The Al(1)-O(6) bond length is 1.88 Å. The Al(1)-O(8) bond length is 2.00 Å. In the second Al site, Al(2) is bonded to one O(11), one O(14), one O(20), one O(25), one O(3), and one O(6) atom to form a mixture of edge, face, and corner-sharing AlO6 octahedra. The corner-sharing octahedral tilt angles range from 48-60°. The Al(2)-O(11) bond length is 2.00 Å. The Al(2)-O(14) bond length is 1.99 Å. The Al(2)-O(20) bond length is 1.88 Å. The Al(2)-O(25) bond length is 1.99 Å. The Al(2)-O(3) bond length is 1.87 Å. The Al(2)-O(6) bond length is 1.88 Å. In the third Al site, Al(3) is bonded to one O(1), one O(12), one O(14), one O(23), one O(3), and one O(5) atom to form a mixture of edge, face, and corner-sharing AlO6 octahedra. The corner-sharing octahedral tilt angles range from 48-60°. The Al(3)-O(1) bond length is 1.88 Å. The Al(3)-O(12) bond length is 1.88 Å. The Al(3)-O(14) bond length is 1.88 Å. The Al(3)-O(23) bond length is 2.00 Å. The Al(3)-O(3) bond length is 2.00 Å. The Al(3)-O(5) bond length is 1.99 Å. In the fourth Al site, Al(4) is bonded to one O(11), one O(2), one O(20), one O(25), one O(4), and one O(6) atom to form AlO6 octahedra that share  a cornercorner with one Al(14)O6 octahedra, corners with two equivalent Al(9)O6 octahedra, corners with three equivalent Al(1)O6 octahedra, corners with three equivalent Al(8)O6 octahedra,  an edgeedge with one Cr(1)O6 octahedra, edges with two equivalent Al(2)O6 octahedra, and  a faceface with one Al(9)O6 octahedra. The corner-sharing octahedral tilt angles range from 45-60°. The Al(4)-O(11) bond length is 1.87 Å. The Al(4)-O(2) bond length is 1.87 Å. The Al(4)-O(20) bond length is 1.99 Å. The Al(4)-O(25) bond length is 1.87 Å. The Al(4)-O(4) bond length is 1.98 Å. The Al(4)-O(6) bond length is 1.99 Å. In the fifth Al site, Al(5) is bonded to one O(1), one O(15), one O(16), one O(19), one O(26), and one O(30) atom to form a mixture of edge, face, and corner-sharing AlO6 octahedra. The corner-sharing octahedral tilt angles range from 48-60°. The Al(5)-O(1) bond length is 1.88 Å. The Al(5)-O(15) bond length is 1.88 Å. The Al(5)-O(16) bond length is 2.00 Å. The Al(5)-O(19) bond length is 1.99 Å. The Al(5)-O(26) bond length is 1.88 Å. The Al(5)-O(30) bond length is 1.99 Å. In the sixth Al site, Al(6) is bonded to one O(18), one O(19), one O(26), one O(27), one O(7), and one O(9) atom to form a mixture of edge, face, and corner-sharing AlO6 octahedra. The corner-sharing octahedral tilt angles range from 48-60°. The Al(6)-O(18) bond length is 1.88 Å. The Al(6)-O(19) bond length is 1.88 Å. The Al(6)-O(26) bond length is 2.00 Å. The Al(6)-O(27) bond length is 1.99 Å. The Al(6)-O(7) bond length is 1.87 Å. The Al(6)-O(9) bond length is 2.00 Å. In the seventh Al site, Al(7) is bonded to one O(1), one O(12), one O(15), one O(16), one O(23), and one O(5) atom to form a mixture of edge, face, and corner-sharing AlO6 octahedra. The corner-sharing octahedral tilt angles range from 48-60°. The Al(7)-O(1) bond length is 2.00 Å. The Al(7)-O(12) bond length is 2.00 Å. The Al(7)-O(15) bond length is 1.99 Å. The Al(7)-O(16) bond length is 1.88 Å. The Al(7)-O(23) bond length is 1.88 Å. The Al(7)-O(5) bond length is 1.88 Å. In the eighth Al site, Al(8) is bonded to one O(11), one O(14), one O(20), one O(23), one O(25), and one O(3) atom to form a mixture of edge, face, and corner-sharing AlO6 octahedra. The corner-sharing octahedral tilt angles range from 47-60°. The Al(8)-O(11) bond length is 2.00 Å. The Al(8)-O(14) bond length is 1.99 Å. The Al(8)-O(20) bond length is 1.87 Å. The Al(8)-O(23) bond length is 1.87 Å. The Al(8)-O(25) bond length is 2.00 Å. The Al(8)-O(3) bond length is 1.88 Å. In the ninth Al site, Al(9) is bonded to one O(11), one O(2), one O(20), one O(4), one O(6), and one O(8) atom to form AlO6 octahedra that share  a cornercorner with one Al(19)O6 octahedra, corners with two equivalent Al(4)O6 octahedra, corners with three equivalent Cr(1)O6 octahedra, corners with three equivalent Al(2)O6 octahedra,  an edgeedge with one Al(8)O6 octahedra, edges with two equivalent Al(1)O6 octahedra, and  a faceface with one Al(4)O6 octahedra. The corner-sharing octahedral tilt angles range from 48-59°. The Al(9)-O(11) bond length is 1.87 Å. The Al(9)-O(2) bond length is 1.87 Å. The Al(9)-O(20) bond length is 1.99 Å. The Al(9)-O(4) bond length is 1.95 Å. The Al(9)-O(6) bond length is 1.99 Å. The Al(9)-O(8) bond length is 1.88 Å. In the tenth Al site, Al(10) is bonded to one O(15), one O(16), one O(19), one O(26), one O(30), and one O(9) atom to form a mixture of edge, face, and corner-sharing AlO6 octahedra. The corner-sharing octahedral tilt angles range from 48-60°. The Al(10)-O(15) bond length is 1.88 Å. The Al(10)-O(16) bond length is 2.00 Å. The Al(10)-O(19) bond length is 2.00 Å. The Al(10)-O(26) bond length is 1.88 Å. The Al(10)-O(30) bond length is 2.00 Å. The Al(10)-O(9) bond length is 1.87 Å. In the eleventh Al site, Al(11) is bonded to one O(13), one O(21), one O(22), one O(24), one O(28), and one O(29) atom to form AlO6 octahedra that share  a cornercorner with one Cr(1)O6 octahedra, corners with two equivalent Al(13)O6 octahedra, corners with three equivalent Al(18)O6 octahedra, corners with three equivalent Al(19)O6 octahedra,  an edgeedge with one Al(12)O6 octahedra, edges with two equivalent Al(16)O6 octahedra, and  a faceface with one Al(13)O6 octahedra. The corner-sharing octahedral tilt angles range from 45-61°. The Al(11)-O(13) bond length is 1.98 Å. The Al(11)-O(21) bond length is 1.87 Å. The Al(11)-O(22) bond length is 1.85 Å. The Al(11)-O(24) bond length is 2.00 Å. The Al(11)-O(28) bond length is 2.00 Å. The Al(11)-O(29) bond length is 1.87 Å. In the twelfth Al site, Al(12) is bonded to one O(13), one O(18), one O(21), one O(27), one O(7), and one O(9) atom to form a mixture of edge, face, and corner-sharing AlO6 octahedra. The corner-sharing octahedral tilt angles range from 47-60°. The Al(12)-O(13) bond length is 1.88 Å. The Al(12)-O(18) bond length is 2.00 Å. The Al(12)-O(21) bond length is 1.99 Å. The Al(12)-O(27) bond length is 1.88 Å. The Al(12)-O(7) bond length is 1.99 Å. The Al(12)-O(9) bond length is 1.88 Å. In the thirteenth Al site, Al(13) is bonded to one O(13), one O(21), one O(24), one O(28), one O(29), and one O(7) atom to form a mixture of edge, face, and corner-sharing AlO6 octahedra. The corner-sharing octahedral tilt angles range from 47-60°. The Al(13)-O(13) bond length is 2.00 Å. The Al(13)-O(21) bond length is 1.88 Å. The Al(13)-O(24) bond length is 1.99 Å. The Al(13)-O(28) bond length is 2.00 Å. The Al(13)-O(29) bond length is 1.88 Å. The Al(13)-O(7) bond length is 1.87 Å. In the fourteenth Al site, Al(14) is bonded to one O(12), one O(14), one O(23), one O(25), one O(3), and one O(5) atom to form a mixture of edge, face, and corner-sharing AlO6 octahedra. The corner-sharing octahedral tilt angles range from 48-60°. The Al(14)-O(12) bond length is 1.88 Å. The Al(14)-O(14) bond length is 1.88 Å. The Al(14)-O(23) bond length is 1.99 Å. The Al(14)-O(25) bond length is 1.88 Å. The Al(14)-O(3) bond length is 1.99 Å. The Al(14)-O(5) bond length is 1.99 Å. In the fifteenth Al site, Al(15) is bonded to one O(18), one O(19), one O(26), one O(27), one O(30), and one O(9) atom to form a mixture of edge, face, and corner-sharing AlO6 octahedra. The corner-sharing octahedral tilt angles range from 48-60°. The Al(15)-O(18) bond length is 1.88 Å. The Al(15)-O(19) bond length is 1.88 Å. The Al(15)-O(26) bond length is 2.00 Å. The Al(15)-O(27) bond length is 1.99 Å. The Al(15)-O(30) bond length is 1.88 Å. The Al(15)-O(9) bond length is 2.00 Å. In the sixteenth Al site, Al(16) is bonded to one O(10), one O(17), one O(22), one O(24), one O(28), and one O(29) atom to form AlO6 octahedra that share  a cornercorner with one Al(18)O6 octahedra, corners with two equivalent Al(19)O6 octahedra, corners with three equivalent Cr(1)O6 octahedra, corners with three equivalent Al(13)O6 octahedra,  an edgeedge with one Al(1)O6 octahedra, edges with two equivalent Al(11)O6 octahedra, and  a faceface with one Al(19)O6 octahedra. The corner-sharing octahedral tilt angles range from 48-60°. The Al(16)-O(10) bond length is 1.88 Å. The Al(16)-O(17) bond length is 1.97 Å. The Al(16)-O(22) bond length is 1.96 Å. The Al(16)-O(24) bond length is 1.87 Å. The Al(16)-O(28) bond length is 1.88 Å. The Al(16)-O(29) bond length is 2.00 Å. In the seventeenth Al site, Al(17) is bonded to one O(1), one O(12), one O(15), one O(16), one O(30), and one O(5) atom to form a mixture of edge, face, and corner-sharing AlO6 octahedra. The corner-sharing octahedral tilt angles range from 48-60°. The Al(17)-O(1) bond length is 2.00 Å. The Al(17)-O(12) bond length is 2.00 Å. The Al(17)-O(15) bond length is 2.00 Å. The Al(17)-O(16) bond length is 1.88 Å. The Al(17)-O(30) bond length is 1.88 Å. The Al(17)-O(5) bond length is 1.88 Å. In the eighteenth Al site, Al(18) is bonded to one O(13), one O(18), one O(21), one O(24), one O(27), and one O(7) atom to form a mixture of edge, face, and corner-sharing AlO6 octahedra. The corner-sharing octahedral tilt angles range from 47-60°. The Al(18)-O(13) bond length is 1.88 Å. The Al(18)-O(18) bond length is 1.99 Å. The Al(18)-O(21) bond length is 1.99 Å. The Al(18)-O(24) bond length is 1.87 Å. The Al(18)-O(27) bond length is 1.88 Å. The Al(18)-O(7) bond length is 2.00 Å. In the nineteenth Al site, Al(19) is bonded to one O(10), one O(17), one O(22), one O(28), one O(29), and one O(8) atom to form AlO6 octahedra that share  a cornercorner with one Al(9)O6 octahedra, corners with two equivalent Al(16)O6 octahedra, corners with three equivalent Al(1)O6 octahedra, corners with three equivalent Al(11)O6 octahedra,  an edgeedge with one Al(13)O6 octahedra, edges with two equivalent Cr(1)O6 octahedra, and  a faceface with one Al(16)O6 octahedra. The corner-sharing octahedral tilt angles range from 44-59°. The Al(19)-O(10) bond length is 1.87 Å. The Al(19)-O(17) bond length is 1.99 Å. The Al(19)-O(22) bond length is 1.98 Å. The Al(19)-O(28) bond length is 1.87 Å. The Al(19)-O(29) bond length is 1.99 Å. The Al(19)-O(8) bond length is 1.89 Å. There are thirty inequivalent O sites. In the first O site, O(1) is bonded to one Al(17), one Al(3), one Al(5), and one Al(7) atom to form a mixture of distorted edge and corner-sharing OAl4 trigonal pyramids. In the second O site, O(2) is bonded to one Cr(1), one Al(1), one Al(4), and one Al(9) atom to form distorted OAl3Cr trigonal pyramids that share  a cornercorner with one O(8)Al3Cr trigonal pyramid,  a cornercorner with one O(25)Al4 trigonal pyramid, corners with two equivalent O(11)Al4 trigonal pyramids, corners with two equivalent O(20)Al4 trigonal pyramids, corners with three equivalent O(6)Al4 trigonal pyramids,  an edgeedge with one O(10)Al3Cr trigonal pyramid, and  an edgeedge with one O(8)Al3Cr trigonal pyramid. In the third O site, O(3) is bonded to one Al(14), one Al(2), one Al(3), and one Al(8) atom to form a mixture of distorted edge and corner-sharing OAl4 trigonal pyramids. In the fourth O site, O(4) is bonded in a distorted see-saw-like geometry to one Cr(1), one Al(1), one Al(4), and one Al(9) atom. In the fifth O site, O(5) is bonded to one Al(14), one Al(17), one Al(3), and one Al(7) atom to form a mixture of distorted edge and corner-sharing OAl4 trigonal pyramids. In the sixth O site, O(6) is bonded to one Al(1), one Al(2), one Al(4), and one Al(9) atom to form distorted OAl4 trigonal pyramids that share  a cornercorner with one O(10)Al3Cr trigonal pyramid,  a cornercorner with one O(14)Al4 trigonal pyramid,  a cornercorner with one O(20)Al4 trigonal pyramid,  a cornercorner with one O(3)Al4 trigonal pyramid, corners with three equivalent O(2)Al3Cr trigonal pyramids, corners with three equivalent O(11)Al4 trigonal pyramids,  an edgeedge with one O(8)Al3Cr trigonal pyramid,  an edgeedge with one O(20)Al4 trigonal pyramid, and  an edgeedge with one O(25)Al4 trigonal pyramid. In the seventh O site, O(7) is bonded to one Al(12), one Al(13), one Al(18), and one Al(6) atom to form a mixture of distorted edge and corner-sharing OAl4 trigonal pyramids. In the eighth O site, O(8) is bonded to one Cr(1), one Al(1), one Al(19), and one Al(9) atom to form distorted OAl3Cr trigonal pyramids that share  a cornercorner with one O(10)Al3Cr trigonal pyramid,  a cornercorner with one O(2)Al3Cr trigonal pyramid,  a cornercorner with one O(11)Al4 trigonal pyramid,  a cornercorner with one O(20)Al4 trigonal pyramid,  a cornercorner with one O(28)Al4 trigonal pyramid,  a cornercorner with one O(29)Al4 trigonal pyramid,  an edgeedge with one O(10)Al3Cr trigonal pyramid,  an edgeedge with one O(2)Al3Cr trigonal pyramid, and  an edgeedge with one O(6)Al4 trigonal pyramid. In the ninth O site, O(9) is bonded to one Al(10), one Al(12), one Al(15), and one Al(6) atom to form a mixture of distorted edge and corner-sharing OAl4 trigonal pyramids. In the tenth O site, O(10) is bonded to one Cr(1), one Al(1), one Al(16), and one Al(19) atom to form distorted OAl3Cr trigonal pyramids that share  a cornercorner with one O(8)Al3Cr trigonal pyramid,  a cornercorner with one O(24)Al4 trigonal pyramid,  a cornercorner with one O(6)Al4 trigonal pyramid, corners with two equivalent O(28)Al4 trigonal pyramids, corners with two equivalent O(29)Al4 trigonal pyramids,  an edgeedge with one O(2)Al3Cr trigonal pyramid, and  an edgeedge with one O(8)Al3Cr trigonal pyramid. In the eleventh O site, O(11) is bonded to one Al(2), one Al(4), one Al(8), and one Al(9) atom to form distorted OAl4 trigonal pyramids that share  a cornercorner with one O(8)Al3Cr trigonal pyramid,  a cornercorner with one O(23)Al4 trigonal pyramid,  a cornercorner with one O(25)Al4 trigonal pyramid, corners with two equivalent O(2)Al3Cr trigonal pyramids, corners with two equivalent O(3)Al4 trigonal pyramids, corners with three equivalent O(6)Al4 trigonal pyramids,  an edgeedge with one O(14)Al4 trigonal pyramid,  an edgeedge with one O(25)Al4 trigonal pyramid, and edges with two equivalent O(20)Al4 trigonal pyramids. In the twelfth O site, O(12) is bonded to one Al(14), one Al(17), one Al(3), and one Al(7) atom to form a mixture of distorted edge and corner-sharing OAl4 trigonal pyramids. In the thirteenth O site, O(13) is bonded to one Al(11), one Al(12), one Al(13), and one Al(18) atom to form a mixture of distorted edge and corner-sharing OAl4 trigonal pyramids. In the fourteenth O site, O(14) is bonded to one Al(14), one Al(2), one Al(3), and one Al(8) atom to form a mixture of distorted edge and corner-sharing OAl4 trigonal pyramids. In the fifteenth O site, O(15) is bonded to one Al(10), one Al(17), one Al(5), and one Al(7) atom to form a mixture of distorted edge and corner-sharing OAl4 trigonal pyramids. In the sixteenth O site, O(16) is bonded to one Al(10), one Al(17), one Al(5), and one Al(7) atom to form a mixture of distorted edge and corner-sharing OAl4 trigonal pyramids. In the seventeenth O site, O(17) is bonded in a distorted see-saw-like geometry to one Cr(1), one Al(1), one Al(16), and one Al(19) atom. In the eighteenth O site, O(18) is bonded to one Al(12), one Al(15), one Al(18), and one Al(6) atom to form a mixture of distorted edge and corner-sharing OAl4 trigonal pyramids. In the nineteenth O site, O(19) is bonded to one Al(10), one Al(15), one Al(5), and one Al(6) atom to form a mixture of distorted edge and corner-sharing OAl4 trigonal pyramids. In the twentieth O site, O(20) is bonded to one Al(2), one Al(4), one Al(8), and one Al(9) atom to form distorted OAl4 trigonal pyramids that share  a cornercorner with one O(8)Al3Cr trigonal pyramid,  a cornercorner with one O(23)Al4 trigonal pyramid,  a cornercorner with one O(6)Al4 trigonal pyramid, corners with two equivalent O(2)Al3Cr trigonal pyramids, corners with two equivalent O(14)Al4 trigonal pyramids, corners with two equivalent O(3)Al4 trigonal pyramids, corners with three equivalent O(25)Al4 trigonal pyramids,  an edgeedge with one O(6)Al4 trigonal pyramid, and edges with two equivalent O(11)Al4 trigonal pyramids. In the twenty-first O site, O(21) is bonded to one Al(11), one Al(12), one Al(13), and one Al(18) atom to form a mixture of distorted edge and corner-sharing OAl4 trigonal pyramids. In the twenty-second O site, O(22) is bonded in a rectangular see-saw-like geometry to one Cr(1), one Al(11), one Al(16), and one Al(19) atom. In the twenty-third O site, O(23) is bonded to one Al(14), one Al(3), one Al(7), and one Al(8) atom to form a mixture of distorted edge and corner-sharing OAl4 trigonal pyramids. In the twenty-fourth O site, O(24) is bonded to one Al(11), one Al(13), one Al(16), and one Al(18) atom to form distorted OAl4 trigonal pyramids that share  a cornercorner with one O(10)Al3Cr trigonal pyramid,  a cornercorner with one O(13)Al4 trigonal pyramid,  a cornercorner with one O(18)Al4 trigonal pyramid,  a cornercorner with one O(27)Al4 trigonal pyramid,  a cornercorner with one O(28)Al4 trigonal pyramid, corners with three equivalent O(21)Al4 trigonal pyramids, corners with three equivalent O(29)Al4 trigonal pyramids,  an edgeedge with one O(13)Al4 trigonal pyramid,  an edgeedge with one O(28)Al4 trigonal pyramid, and  an edgeedge with one O(7)Al4 trigonal pyramid. In the twenty-fifth O site, O(25) is bonded to one Al(14), one Al(2), one Al(4), and one Al(8) atom to form distorted OAl4 trigonal pyramids that share  a cornercorner with one O(2)Al3Cr trigonal pyramid,  a cornercorner with one O(11)Al4 trigonal pyramid,  a cornercorner with one O(12)Al4 trigonal pyramid,  a cornercorner with one O(14)Al4 trigonal pyramid,  a cornercorner with one O(5)Al4 trigonal pyramid, corners with three equivalent O(20)Al4 trigonal pyramids, corners with three equivalent O(3)Al4 trigonal pyramids,  an edgeedge with one O(11)Al4 trigonal pyramid,  an edgeedge with one O(14)Al4 trigonal pyramid,  an edgeedge with one O(23)Al4 trigonal pyramid, and  an edgeedge with one O(6)Al4 trigonal pyramid. In the twenty-sixth O site, O(26) is bonded to one Al(10), one Al(15), one Al(5), and one Al(6) atom to form a mixture of distorted edge and corner-sharing OAl4 trigonal pyramids. In the twenty-seventh O site, O(27) is bonded to one Al(12), one Al(15), one Al(18), and one Al(6) atom to form a mixture of distorted edge and corner-sharing OAl4 trigonal pyramids. In the twenty-eighth O site, O(28) is bonded to one Al(11), one Al(13), one Al(16), and one Al(19) atom to form distorted OAl4 trigonal pyramids that share  a cornercorner with one O(8)Al3Cr trigonal pyramid,  a cornercorner with one O(24)Al4 trigonal pyramid,  a cornercorner with one O(7)Al4 trigonal pyramid, corners with two equivalent O(10)Al3Cr trigonal pyramids, corners with two equivalent O(21)Al4 trigonal pyramids,  an edgeedge with one O(13)Al4 trigonal pyramid,  an edgeedge with one O(24)Al4 trigonal pyramid, and edges with two equivalent O(29)Al4 trigonal pyramids. In the twenty-ninth O site, O(29) is bonded to one Al(11), one Al(13), one Al(16), and one Al(19) atom to form distorted OAl4 trigonal pyramids that share  a cornercorner with one O(8)Al3Cr trigonal pyramid,  a cornercorner with one O(7)Al4 trigonal pyramid, corners with two equivalent O(10)Al3Cr trigonal pyramids, corners with two equivalent O(13)Al4 trigonal pyramids, corners with two equivalent O(21)Al4 trigonal pyramids, corners with three equivalent O(24)Al4 trigonal pyramids, and edges with two equivalent O(28)Al4 trigonal pyramids. In the thirtieth O site, O(30) is bonded to one Al(10), one Al(15), one Al(17), and one Al(5) atom to form a mixture of distorted edge and corner-sharing OAl4 trigonal pyramids.