BaSc6Ni4O15 crystallizes in the orthorhombic Cmce space group. Ba(1) is bonded to two equivalent O(3), two equivalent O(5), four equivalent O(2), and four equivalent O(4) atoms to form distorted BaO12 cuboctahedra that share corners with eight equivalent Sc(2)O6 octahedra, corners with eight equivalent Ni(1)O6 octahedra, edges with two equivalent Sc(1)O6 octahedra, edges with four equivalent Sc(2)O6 octahedra, faces with two equivalent Sc(1)O6 octahedra, and faces with four equivalent Ni(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 18-50°. There are two inequivalent Sc sites. In the first Sc site, Sc(1) is bonded to one O(3), one O(6), two equivalent O(2), and two equivalent O(4) atoms to form distorted ScO6 octahedra that share  a cornercorner with one Sc(1)O6 octahedra, corners with two equivalent Sc(2)O6 octahedra, corners with four equivalent Ni(1)O6 octahedra,  an edgeedge with one Ba(1)O12 cuboctahedra, edges with two equivalent Ni(1)O6 octahedra, edges with four equivalent Sc(2)O6 octahedra, and  a faceface with one Ba(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-57°. In the second Sc site, Sc(2) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(6) atom to form ScO6 octahedra that share corners with two equivalent Ba(1)O12 cuboctahedra,  a cornercorner with one Sc(1)O6 octahedra, corners with two equivalent Sc(2)O6 octahedra, corners with two equivalent Ni(1)O6 octahedra,  an edgeedge with one Ba(1)O12 cuboctahedra, edges with two equivalent Sc(1)O6 octahedra, edges with two equivalent Sc(2)O6 octahedra, and edges with three equivalent Ni(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-66°. Ni(1) is bonded to one O(1), one O(5), two equivalent O(2), and two equivalent O(4) atoms to form NiO6 octahedra that share corners with two equivalent Ba(1)O12 cuboctahedra,  a cornercorner with one Ni(1)O6 octahedra, corners with two equivalent Sc(1)O6 octahedra, corners with two equivalent Sc(2)O6 octahedra,  an edgeedge with one Sc(1)O6 octahedra,  an edgeedge with one Ni(1)O6 octahedra, edges with three equivalent Sc(2)O6 octahedra,  a faceface with one Ba(1)O12 cuboctahedra, and  a faceface with one Ni(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 4-53°. There are six inequivalent O sites. In the first O site, O(5) is bonded to one Ba(1), two equivalent Sc(2), and two equivalent Ni(1) atoms to form distorted OBaSc2Ni2 trigonal bipyramids that share corners with four equivalent O(3)BaSc3 tetrahedra,  a cornercorner with one O(5)BaSc2Ni2 trigonal bipyramid, corners with two equivalent O(2)BaSc2Ni2 trigonal pyramids,  an edgeedge with one O(6)Sc6 octahedra, and edges with four equivalent O(2)BaSc2Ni2 trigonal pyramids. In the second O site, O(6) is bonded to two equivalent Sc(1) and four equivalent Sc(2) atoms to form OSc6 octahedra that share corners with two equivalent O(3)BaSc3 tetrahedra, edges with two equivalent O(3)BaSc3 tetrahedra, edges with two equivalent O(5)BaSc2Ni2 trigonal bipyramids, and edges with four equivalent O(2)BaSc2Ni2 trigonal pyramids. In the third O site, O(1) is bonded in a distorted see-saw-like geometry to two equivalent Sc(2) and two equivalent Ni(1) atoms. In the fourth O site, O(4) is bonded in a distorted rectangular see-saw-like geometry to one Ba(1), one Sc(1), one Sc(2), and two equivalent Ni(1) atoms. In the fifth O site, O(2) is bonded to one Ba(1), one Sc(1), one Sc(2), and two equivalent Ni(1) atoms to form distorted OBaSc2Ni2 trigonal pyramids that share corners with two equivalent O(3)BaSc3 tetrahedra,  a cornercorner with one O(5)BaSc2Ni2 trigonal bipyramid, corners with two equivalent O(2)BaSc2Ni2 trigonal pyramids,  an edgeedge with one O(6)Sc6 octahedra,  an edgeedge with one O(3)BaSc3 tetrahedra, edges with two equivalent O(5)BaSc2Ni2 trigonal bipyramids, and edges with two equivalent O(2)BaSc2Ni2 trigonal pyramids. In the sixth O site, O(3) is bonded to one Ba(1), one Sc(1), and two equivalent Sc(2) atoms to form distorted OBaSc3 tetrahedra that share  a cornercorner with one O(6)Sc6 octahedra,  a cornercorner with one O(3)BaSc3 tetrahedra, corners with four equivalent O(5)BaSc2Ni2 trigonal bipyramids, corners with four equivalent O(2)BaSc2Ni2 trigonal pyramids,  an edgeedge with one O(6)Sc6 octahedra, and edges with two equivalent O(2)BaSc2Ni2 trigonal pyramids. The corner-sharing octahedral tilt angles are 6°.
BaSc6Ni4O15 crystallizes in the orthorhombic Cmce space group. Ba(1) is bonded to two equivalent O(3), two equivalent O(5), four equivalent O(2), and four equivalent O(4) atoms to form distorted BaO12 cuboctahedra that share corners with eight equivalent Sc(2)O6 octahedra, corners with eight equivalent Ni(1)O6 octahedra, edges with two equivalent Sc(1)O6 octahedra, edges with four equivalent Sc(2)O6 octahedra, faces with two equivalent Sc(1)O6 octahedra, and faces with four equivalent Ni(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 18-50°. Both Ba(1)-O(3) bond lengths are 2.80 Å. Both Ba(1)-O(5) bond lengths are 2.95 Å. All Ba(1)-O(2) bond lengths are 3.08 Å. All Ba(1)-O(4) bond lengths are 3.23 Å. There are two inequivalent Sc sites. In the first Sc site, Sc(1) is bonded to one O(3), one O(6), two equivalent O(2), and two equivalent O(4) atoms to form distorted ScO6 octahedra that share  a cornercorner with one Sc(1)O6 octahedra, corners with two equivalent Sc(2)O6 octahedra, corners with four equivalent Ni(1)O6 octahedra,  an edgeedge with one Ba(1)O12 cuboctahedra, edges with two equivalent Ni(1)O6 octahedra, edges with four equivalent Sc(2)O6 octahedra, and  a faceface with one Ba(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-57°. The Sc(1)-O(3) bond length is 2.01 Å. The Sc(1)-O(6) bond length is 2.41 Å. Both Sc(1)-O(2) bond lengths are 2.13 Å. Both Sc(1)-O(4) bond lengths are 2.13 Å. In the second Sc site, Sc(2) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(6) atom to form ScO6 octahedra that share corners with two equivalent Ba(1)O12 cuboctahedra,  a cornercorner with one Sc(1)O6 octahedra, corners with two equivalent Sc(2)O6 octahedra, corners with two equivalent Ni(1)O6 octahedra,  an edgeedge with one Ba(1)O12 cuboctahedra, edges with two equivalent Sc(1)O6 octahedra, edges with two equivalent Sc(2)O6 octahedra, and edges with three equivalent Ni(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-66°. The Sc(2)-O(1) bond length is 2.05 Å. The Sc(2)-O(2) bond length is 2.10 Å. The Sc(2)-O(3) bond length is 2.06 Å. The Sc(2)-O(4) bond length is 2.10 Å. The Sc(2)-O(5) bond length is 2.19 Å. The Sc(2)-O(6) bond length is 2.31 Å. Ni(1) is bonded to one O(1), one O(5), two equivalent O(2), and two equivalent O(4) atoms to form NiO6 octahedra that share corners with two equivalent Ba(1)O12 cuboctahedra,  a cornercorner with one Ni(1)O6 octahedra, corners with two equivalent Sc(1)O6 octahedra, corners with two equivalent Sc(2)O6 octahedra,  an edgeedge with one Sc(1)O6 octahedra,  an edgeedge with one Ni(1)O6 octahedra, edges with three equivalent Sc(2)O6 octahedra,  a faceface with one Ba(1)O12 cuboctahedra, and  a faceface with one Ni(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 4-53°. The Ni(1)-O(1) bond length is 2.04 Å. The Ni(1)-O(5) bond length is 2.08 Å. There is one shorter (2.06 Å) and one longer (2.12 Å) Ni(1)-O(2) bond length. There is one shorter (2.05 Å) and one longer (2.06 Å) Ni(1)-O(4) bond length. There are six inequivalent O sites. In the first O site, O(5) is bonded to one Ba(1), two equivalent Sc(2), and two equivalent Ni(1) atoms to form distorted OBaSc2Ni2 trigonal bipyramids that share corners with four equivalent O(3)BaSc3 tetrahedra,  a cornercorner with one O(5)BaSc2Ni2 trigonal bipyramid, corners with two equivalent O(2)BaSc2Ni2 trigonal pyramids,  an edgeedge with one O(6)Sc6 octahedra, and edges with four equivalent O(2)BaSc2Ni2 trigonal pyramids. In the second O site, O(6) is bonded to two equivalent Sc(1) and four equivalent Sc(2) atoms to form OSc6 octahedra that share corners with two equivalent O(3)BaSc3 tetrahedra, edges with two equivalent O(3)BaSc3 tetrahedra, edges with two equivalent O(5)BaSc2Ni2 trigonal bipyramids, and edges with four equivalent O(2)BaSc2Ni2 trigonal pyramids. In the third O site, O(1) is bonded in a distorted see-saw-like geometry to two equivalent Sc(2) and two equivalent Ni(1) atoms. In the fourth O site, O(4) is bonded in a distorted rectangular see-saw-like geometry to one Ba(1), one Sc(1), one Sc(2), and two equivalent Ni(1) atoms. In the fifth O site, O(2) is bonded to one Ba(1), one Sc(1), one Sc(2), and two equivalent Ni(1) atoms to form distorted OBaSc2Ni2 trigonal pyramids that share corners with two equivalent O(3)BaSc3 tetrahedra,  a cornercorner with one O(5)BaSc2Ni2 trigonal bipyramid, corners with two equivalent O(2)BaSc2Ni2 trigonal pyramids,  an edgeedge with one O(6)Sc6 octahedra,  an edgeedge with one O(3)BaSc3 tetrahedra, edges with two equivalent O(5)BaSc2Ni2 trigonal bipyramids, and edges with two equivalent O(2)BaSc2Ni2 trigonal pyramids. In the sixth O site, O(3) is bonded to one Ba(1), one Sc(1), and two equivalent Sc(2) atoms to form distorted OBaSc3 tetrahedra that share  a cornercorner with one O(6)Sc6 octahedra,  a cornercorner with one O(3)BaSc3 tetrahedra, corners with four equivalent O(5)BaSc2Ni2 trigonal bipyramids, corners with four equivalent O(2)BaSc2Ni2 trigonal pyramids,  an edgeedge with one O(6)Sc6 octahedra, and edges with two equivalent O(2)BaSc2Ni2 trigonal pyramids. The corner-sharing octahedral tilt angles are 6°.