Ba4Ta10CoO30 crystallizes in the orthorhombic Imm2 space group. There are four inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 7-coordinate geometry to one O(7), two equivalent O(1), and four equivalent O(12) atoms. In the second Ba site, Ba(2) is bonded in a 13-coordinate geometry to one O(8), two equivalent O(1), two equivalent O(4), four equivalent O(11), and four equivalent O(12) atoms. In the third Ba site, Ba(3) is bonded in a 9-coordinate geometry to one O(8), two equivalent O(10), two equivalent O(6), and four equivalent O(5) atoms. In the fourth Ba site, Ba(4) is bonded in a 6-coordinate geometry to two equivalent O(6) and four equivalent O(5) atoms. There are three inequivalent Ta sites. In the first Ta site, Ta(1) is bonded to one O(7), one O(8), two equivalent O(12), and two equivalent O(5) atoms to form corner-sharing TaO6 octahedra. The corner-sharing octahedral tilt angles range from 4-35°. In the second Ta site, Ta(2) is bonded to one O(10), one O(11), one O(12), one O(2), one O(6), and one O(9) atom to form corner-sharing TaO6 octahedra. The corner-sharing octahedral tilt angles range from 3-43°. In the third Ta site, Ta(3) is bonded to one O(1), one O(11), one O(2), one O(3), one O(4), and one O(5) atom to form corner-sharing TaO6 octahedra. The corner-sharing octahedral tilt angles range from 6-39°. Co(1) is bonded in a 6-coordinate geometry to two equivalent O(4) and four equivalent O(2) atoms. There are twelve inequivalent O sites. In the first O site, O(1) is bonded to one Ba(1), one Ba(2), and two equivalent Ta(3) atoms to form distorted corner-sharing OBa2Ta2 trigonal pyramids. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Ta(2), one Ta(3), and one Co(1) atom. In the third O site, O(3) is bonded in a linear geometry to two equivalent Ta(3) atoms. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to one Ba(2), two equivalent Ta(3), and one Co(1) atom. In the fifth O site, O(5) is bonded in a distorted bent 150 degrees geometry to one Ba(3), one Ba(4), one Ta(1), and one Ta(3) atom. In the sixth O site, O(6) is bonded in a 4-coordinate geometry to one Ba(3), one Ba(4), and two equivalent Ta(2) atoms. In the seventh O site, O(7) is bonded in a distorted linear geometry to one Ba(1) and two equivalent Ta(1) atoms. In the eighth O site, O(8) is bonded in a linear geometry to one Ba(2), one Ba(3), and two equivalent Ta(1) atoms. In the ninth O site, O(9) is bonded in a linear geometry to two equivalent Ta(2) atoms. In the tenth O site, O(10) is bonded in a distorted bent 150 degrees geometry to one Ba(3) and two equivalent Ta(2) atoms. In the eleventh O site, O(11) is bonded in a linear geometry to one Ba(2), one Ta(2), and one Ta(3) atom. In the twelfth O site, O(12) is bonded in a distorted bent 150 degrees geometry to one Ba(1), one Ba(2), one Ta(1), and one Ta(2) atom.
Ba4Ta10CoO30 crystallizes in the orthorhombic Imm2 space group. There are four inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 7-coordinate geometry to one O(7), two equivalent O(1), and four equivalent O(12) atoms. The Ba(1)-O(7) bond length is 2.89 Å. Both Ba(1)-O(1) bond lengths are 2.71 Å. All Ba(1)-O(12) bond lengths are 2.83 Å. In the second Ba site, Ba(2) is bonded in a 13-coordinate geometry to one O(8), two equivalent O(1), two equivalent O(4), four equivalent O(11), and four equivalent O(12) atoms. The Ba(2)-O(8) bond length is 3.22 Å. Both Ba(2)-O(1) bond lengths are 2.86 Å. Both Ba(2)-O(4) bond lengths are 2.88 Å. All Ba(2)-O(11) bond lengths are 3.26 Å. All Ba(2)-O(12) bond lengths are 2.93 Å. In the third Ba site, Ba(3) is bonded in a 9-coordinate geometry to one O(8), two equivalent O(10), two equivalent O(6), and four equivalent O(5) atoms. The Ba(3)-O(8) bond length is 3.02 Å. Both Ba(3)-O(10) bond lengths are 2.95 Å. Both Ba(3)-O(6) bond lengths are 2.75 Å. All Ba(3)-O(5) bond lengths are 2.98 Å. In the fourth Ba site, Ba(4) is bonded in a 6-coordinate geometry to two equivalent O(6) and four equivalent O(5) atoms. Both Ba(4)-O(6) bond lengths are 2.74 Å. All Ba(4)-O(5) bond lengths are 2.84 Å. There are three inequivalent Ta sites. In the first Ta site, Ta(1) is bonded to one O(7), one O(8), two equivalent O(12), and two equivalent O(5) atoms to form corner-sharing TaO6 octahedra. The corner-sharing octahedral tilt angles range from 4-35°. The Ta(1)-O(7) bond length is 1.98 Å. The Ta(1)-O(8) bond length is 1.98 Å. Both Ta(1)-O(12) bond lengths are 1.99 Å. Both Ta(1)-O(5) bond lengths are 1.98 Å. In the second Ta site, Ta(2) is bonded to one O(10), one O(11), one O(12), one O(2), one O(6), and one O(9) atom to form corner-sharing TaO6 octahedra. The corner-sharing octahedral tilt angles range from 3-43°. The Ta(2)-O(10) bond length is 2.00 Å. The Ta(2)-O(11) bond length is 2.09 Å. The Ta(2)-O(12) bond length is 1.98 Å. The Ta(2)-O(2) bond length is 1.95 Å. The Ta(2)-O(6) bond length is 2.02 Å. The Ta(2)-O(9) bond length is 1.98 Å. In the third Ta site, Ta(3) is bonded to one O(1), one O(11), one O(2), one O(3), one O(4), and one O(5) atom to form corner-sharing TaO6 octahedra. The corner-sharing octahedral tilt angles range from 6-39°. The Ta(3)-O(1) bond length is 2.02 Å. The Ta(3)-O(11) bond length is 1.93 Å. The Ta(3)-O(2) bond length is 2.08 Å. The Ta(3)-O(3) bond length is 1.96 Å. The Ta(3)-O(4) bond length is 2.04 Å. The Ta(3)-O(5) bond length is 1.98 Å. Co(1) is bonded in a 6-coordinate geometry to two equivalent O(4) and four equivalent O(2) atoms. Both Co(1)-O(4) bond lengths are 2.24 Å. All Co(1)-O(2) bond lengths are 2.20 Å. There are twelve inequivalent O sites. In the first O site, O(1) is bonded to one Ba(1), one Ba(2), and two equivalent Ta(3) atoms to form distorted corner-sharing OBa2Ta2 trigonal pyramids. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Ta(2), one Ta(3), and one Co(1) atom. In the third O site, O(3) is bonded in a linear geometry to two equivalent Ta(3) atoms. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to one Ba(2), two equivalent Ta(3), and one Co(1) atom. In the fifth O site, O(5) is bonded in a distorted bent 150 degrees geometry to one Ba(3), one Ba(4), one Ta(1), and one Ta(3) atom. In the sixth O site, O(6) is bonded in a 4-coordinate geometry to one Ba(3), one Ba(4), and two equivalent Ta(2) atoms. In the seventh O site, O(7) is bonded in a distorted linear geometry to one Ba(1) and two equivalent Ta(1) atoms. In the eighth O site, O(8) is bonded in a linear geometry to one Ba(2), one Ba(3), and two equivalent Ta(1) atoms. In the ninth O site, O(9) is bonded in a linear geometry to two equivalent Ta(2) atoms. In the tenth O site, O(10) is bonded in a distorted bent 150 degrees geometry to one Ba(3) and two equivalent Ta(2) atoms. In the eleventh O site, O(11) is bonded in a linear geometry to one Ba(2), one Ta(2), and one Ta(3) atom. In the twelfth O site, O(12) is bonded in a distorted bent 150 degrees geometry to one Ba(1), one Ba(2), one Ta(1), and one Ta(2) atom.