Sc4Ti3O12 crystallizes in the triclinic P-1 space group. There are four inequivalent Sc sites. In the first Sc site, Sc(1) is bonded in a 7-coordinate geometry to one O(1), one O(10), one O(2), one O(3), one O(8), and two equivalent O(4) atoms. In the second Sc site, Sc(2) is bonded to one O(1), one O(10), one O(12), one O(4), one O(6), one O(8), and one O(9) atom to form distorted ScO7 pentagonal bipyramids that share  a cornercorner with one Ti(2)O6 octahedra,  an edgeedge with one Ti(2)O6 octahedra, and edges with two equivalent Sc(3)O7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 50°. In the third Sc site, Sc(3) is bonded to one O(10), one O(11), one O(12), one O(3), one O(6), one O(7), and one O(9) atom to form distorted ScO7 pentagonal bipyramids that share  a cornercorner with one Ti(2)O6 octahedra,  an edgeedge with one Ti(2)O6 octahedra, and edges with two equivalent Sc(2)O7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 50°. In the fourth Sc site, Sc(4) is bonded in a 7-coordinate geometry to one O(12), one O(7), one O(9), two equivalent O(11), and two equivalent O(5) atoms. There are three inequivalent Ti sites. In the first Ti site, Ti(1) is bonded in a 6-coordinate geometry to one O(11), one O(12), one O(3), one O(5), and two equivalent O(7) atoms. In the second Ti site, Ti(2) is bonded to one O(1), one O(2), one O(3), one O(5), one O(6), and one O(9) atom to form TiO6 octahedra that share  a cornercorner with one Sc(2)O7 pentagonal bipyramid,  a cornercorner with one Sc(3)O7 pentagonal bipyramid,  an edgeedge with one Sc(2)O7 pentagonal bipyramid, and  an edgeedge with one Sc(3)O7 pentagonal bipyramid. In the third Ti site, Ti(3) is bonded in a 6-coordinate geometry to one O(10), one O(2), one O(4), one O(6), and two equivalent O(8) atoms. There are twelve inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal non-coplanar geometry to one Sc(1), one Sc(2), and one Ti(2) atom. In the second O site, O(2) is bonded in a distorted trigonal non-coplanar geometry to one Sc(1), one Ti(2), and one Ti(3) atom. In the third O site, O(3) is bonded in a distorted rectangular see-saw-like geometry to one Sc(1), one Sc(3), one Ti(1), and one Ti(2) atom. In the fourth O site, O(4) is bonded to one Sc(2), two equivalent Sc(1), and one Ti(3) atom to form distorted OSc3Ti trigonal pyramids that share  a cornercorner with one O(12)Sc3Ti tetrahedra,  a cornercorner with one O(9)Sc3Ti tetrahedra, corners with two equivalent O(10)Sc3Ti tetrahedra, corners with three equivalent O(8)Sc2Ti2 tetrahedra, corners with two equivalent O(6)Sc2Ti2 trigonal pyramids,  an edgeedge with one O(8)Sc2Ti2 tetrahedra,  an edgeedge with one O(10)Sc3Ti tetrahedra, and  an edgeedge with one O(4)Sc3Ti trigonal pyramid. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to two equivalent Sc(4), one Ti(1), and one Ti(2) atom. In the sixth O site, O(6) is bonded to one Sc(2), one Sc(3), one Ti(2), and one Ti(3) atom to form distorted OSc2Ti2 trigonal pyramids that share  a cornercorner with one O(7)Sc2Ti2 tetrahedra,  a cornercorner with one O(8)Sc2Ti2 tetrahedra,  a cornercorner with one O(10)Sc3Ti tetrahedra,  a cornercorner with one O(11)Sc3Ti tetrahedra,  a cornercorner with one O(9)Sc3Ti tetrahedra, corners with two equivalent O(12)Sc3Ti tetrahedra, corners with two equivalent O(4)Sc3Ti trigonal pyramids,  an edgeedge with one O(8)Sc2Ti2 tetrahedra,  an edgeedge with one O(10)Sc3Ti tetrahedra, and  an edgeedge with one O(9)Sc3Ti tetrahedra. In the seventh O site, O(7) is bonded to one Sc(3), one Sc(4), and two equivalent Ti(1) atoms to form OSc2Ti2 tetrahedra that share  a cornercorner with one O(10)Sc3Ti tetrahedra, corners with two equivalent O(12)Sc3Ti tetrahedra, corners with two equivalent O(9)Sc3Ti tetrahedra, corners with three equivalent O(11)Sc3Ti tetrahedra,  a cornercorner with one O(6)Sc2Ti2 trigonal pyramid,  an edgeedge with one O(7)Sc2Ti2 tetrahedra,  an edgeedge with one O(11)Sc3Ti tetrahedra, and  an edgeedge with one O(12)Sc3Ti tetrahedra. In the eighth O site, O(8) is bonded to one Sc(1), one Sc(2), and two equivalent Ti(3) atoms to form OSc2Ti2 tetrahedra that share  a cornercorner with one O(12)Sc3Ti tetrahedra,  a cornercorner with one O(9)Sc3Ti tetrahedra, corners with two equivalent O(10)Sc3Ti tetrahedra,  a cornercorner with one O(6)Sc2Ti2 trigonal pyramid, corners with three equivalent O(4)Sc3Ti trigonal pyramids,  an edgeedge with one O(8)Sc2Ti2 tetrahedra,  an edgeedge with one O(10)Sc3Ti tetrahedra,  an edgeedge with one O(6)Sc2Ti2 trigonal pyramid, and  an edgeedge with one O(4)Sc3Ti trigonal pyramid. In the ninth O site, O(9) is bonded to one Sc(2), one Sc(3), one Sc(4), and one Ti(2) atom to form distorted OSc3Ti tetrahedra that share  a cornercorner with one O(8)Sc2Ti2 tetrahedra,  a cornercorner with one O(11)Sc3Ti tetrahedra,  a cornercorner with one O(12)Sc3Ti tetrahedra, corners with two equivalent O(7)Sc2Ti2 tetrahedra, corners with two equivalent O(10)Sc3Ti tetrahedra,  a cornercorner with one O(6)Sc2Ti2 trigonal pyramid,  a cornercorner with one O(4)Sc3Ti trigonal pyramid,  an edgeedge with one O(11)Sc3Ti tetrahedra,  an edgeedge with one O(12)Sc3Ti tetrahedra, and  an edgeedge with one O(6)Sc2Ti2 trigonal pyramid. In the tenth O site, O(10) is bonded to one Sc(1), one Sc(2), one Sc(3), and one Ti(3) atom to form OSc3Ti tetrahedra that share  a cornercorner with one O(7)Sc2Ti2 tetrahedra,  a cornercorner with one O(11)Sc3Ti tetrahedra, corners with two equivalent O(8)Sc2Ti2 tetrahedra, corners with two equivalent O(9)Sc3Ti tetrahedra,  a cornercorner with one O(6)Sc2Ti2 trigonal pyramid, corners with two equivalent O(4)Sc3Ti trigonal pyramids,  an edgeedge with one O(8)Sc2Ti2 tetrahedra,  an edgeedge with one O(12)Sc3Ti tetrahedra,  an edgeedge with one O(6)Sc2Ti2 trigonal pyramid, and  an edgeedge with one O(4)Sc3Ti trigonal pyramid. In the eleventh O site, O(11) is bonded to one Sc(3), two equivalent Sc(4), and one Ti(1) atom to form OSc3Ti tetrahedra that share  a cornercorner with one O(10)Sc3Ti tetrahedra,  a cornercorner with one O(9)Sc3Ti tetrahedra, corners with two equivalent O(12)Sc3Ti tetrahedra, corners with three equivalent O(7)Sc2Ti2 tetrahedra,  a cornercorner with one O(6)Sc2Ti2 trigonal pyramid,  an edgeedge with one O(7)Sc2Ti2 tetrahedra,  an edgeedge with one O(11)Sc3Ti tetrahedra,  an edgeedge with one O(12)Sc3Ti tetrahedra, and  an edgeedge with one O(9)Sc3Ti tetrahedra. In the twelfth O site, O(12) is bonded to one Sc(2), one Sc(3), one Sc(4), and one Ti(1) atom to form distorted OSc3Ti tetrahedra that share  a cornercorner with one O(8)Sc2Ti2 tetrahedra,  a cornercorner with one O(9)Sc3Ti tetrahedra, corners with two equivalent O(7)Sc2Ti2 tetrahedra, corners with two equivalent O(11)Sc3Ti tetrahedra,  a cornercorner with one O(4)Sc3Ti trigonal pyramid, corners with two equivalent O(6)Sc2Ti2 trigonal pyramids,  an edgeedge with one O(7)Sc2Ti2 tetrahedra,  an edgeedge with one O(10)Sc3Ti tetrahedra,  an edgeedge with one O(11)Sc3Ti tetrahedra, and  an edgeedge with one O(9)Sc3Ti tetrahedra.
Sc4Ti3O12 crystallizes in the triclinic P-1 space group. There are four inequivalent Sc sites. In the first Sc site, Sc(1) is bonded in a 7-coordinate geometry to one O(1), one O(10), one O(2), one O(3), one O(8), and two equivalent O(4) atoms. The Sc(1)-O(1) bond length is 2.06 Å. The Sc(1)-O(10) bond length is 2.05 Å. The Sc(1)-O(2) bond length is 2.12 Å. The Sc(1)-O(3) bond length is 2.57 Å. The Sc(1)-O(8) bond length is 2.20 Å. There is one shorter (2.14 Å) and one longer (2.22 Å) Sc(1)-O(4) bond length. In the second Sc site, Sc(2) is bonded to one O(1), one O(10), one O(12), one O(4), one O(6), one O(8), and one O(9) atom to form distorted ScO7 pentagonal bipyramids that share  a cornercorner with one Ti(2)O6 octahedra,  an edgeedge with one Ti(2)O6 octahedra, and edges with two equivalent Sc(3)O7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 50°. The Sc(2)-O(1) bond length is 2.09 Å. The Sc(2)-O(10) bond length is 2.17 Å. The Sc(2)-O(12) bond length is 2.14 Å. The Sc(2)-O(4) bond length is 2.27 Å. The Sc(2)-O(6) bond length is 2.41 Å. The Sc(2)-O(8) bond length is 2.08 Å. The Sc(2)-O(9) bond length is 2.14 Å. In the third Sc site, Sc(3) is bonded to one O(10), one O(11), one O(12), one O(3), one O(6), one O(7), and one O(9) atom to form distorted ScO7 pentagonal bipyramids that share  a cornercorner with one Ti(2)O6 octahedra,  an edgeedge with one Ti(2)O6 octahedra, and edges with two equivalent Sc(2)O7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 50°. The Sc(3)-O(10) bond length is 2.13 Å. The Sc(3)-O(11) bond length is 2.03 Å. The Sc(3)-O(12) bond length is 2.24 Å. The Sc(3)-O(3) bond length is 2.19 Å. The Sc(3)-O(6) bond length is 2.20 Å. The Sc(3)-O(7) bond length is 2.25 Å. The Sc(3)-O(9) bond length is 2.30 Å. In the fourth Sc site, Sc(4) is bonded in a 7-coordinate geometry to one O(12), one O(7), one O(9), two equivalent O(11), and two equivalent O(5) atoms. The Sc(4)-O(12) bond length is 2.28 Å. The Sc(4)-O(7) bond length is 2.07 Å. The Sc(4)-O(9) bond length is 2.16 Å. There is one shorter (2.11 Å) and one longer (2.12 Å) Sc(4)-O(11) bond length. There is one shorter (2.15 Å) and one longer (2.55 Å) Sc(4)-O(5) bond length. There are three inequivalent Ti sites. In the first Ti site, Ti(1) is bonded in a 6-coordinate geometry to one O(11), one O(12), one O(3), one O(5), and two equivalent O(7) atoms. The Ti(1)-O(11) bond length is 2.13 Å. The Ti(1)-O(12) bond length is 1.91 Å. The Ti(1)-O(3) bond length is 2.02 Å. The Ti(1)-O(5) bond length is 1.94 Å. There is one shorter (1.96 Å) and one longer (2.17 Å) Ti(1)-O(7) bond length. In the second Ti site, Ti(2) is bonded to one O(1), one O(2), one O(3), one O(5), one O(6), and one O(9) atom to form TiO6 octahedra that share  a cornercorner with one Sc(2)O7 pentagonal bipyramid,  a cornercorner with one Sc(3)O7 pentagonal bipyramid,  an edgeedge with one Sc(2)O7 pentagonal bipyramid, and  an edgeedge with one Sc(3)O7 pentagonal bipyramid. The Ti(2)-O(1) bond length is 1.88 Å. The Ti(2)-O(2) bond length is 1.90 Å. The Ti(2)-O(3) bond length is 2.01 Å. The Ti(2)-O(5) bond length is 2.15 Å. The Ti(2)-O(6) bond length is 2.09 Å. The Ti(2)-O(9) bond length is 1.95 Å. In the third Ti site, Ti(3) is bonded in a 6-coordinate geometry to one O(10), one O(2), one O(4), one O(6), and two equivalent O(8) atoms. The Ti(3)-O(10) bond length is 2.04 Å. The Ti(3)-O(2) bond length is 2.04 Å. The Ti(3)-O(4) bond length is 1.89 Å. The Ti(3)-O(6) bond length is 1.96 Å. There is one shorter (1.96 Å) and one longer (2.10 Å) Ti(3)-O(8) bond length. There are twelve inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal non-coplanar geometry to one Sc(1), one Sc(2), and one Ti(2) atom. In the second O site, O(2) is bonded in a distorted trigonal non-coplanar geometry to one Sc(1), one Ti(2), and one Ti(3) atom. In the third O site, O(3) is bonded in a distorted rectangular see-saw-like geometry to one Sc(1), one Sc(3), one Ti(1), and one Ti(2) atom. In the fourth O site, O(4) is bonded to one Sc(2), two equivalent Sc(1), and one Ti(3) atom to form distorted OSc3Ti trigonal pyramids that share  a cornercorner with one O(12)Sc3Ti tetrahedra,  a cornercorner with one O(9)Sc3Ti tetrahedra, corners with two equivalent O(10)Sc3Ti tetrahedra, corners with three equivalent O(8)Sc2Ti2 tetrahedra, corners with two equivalent O(6)Sc2Ti2 trigonal pyramids,  an edgeedge with one O(8)Sc2Ti2 tetrahedra,  an edgeedge with one O(10)Sc3Ti tetrahedra, and  an edgeedge with one O(4)Sc3Ti trigonal pyramid. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to two equivalent Sc(4), one Ti(1), and one Ti(2) atom. In the sixth O site, O(6) is bonded to one Sc(2), one Sc(3), one Ti(2), and one Ti(3) atom to form distorted OSc2Ti2 trigonal pyramids that share  a cornercorner with one O(7)Sc2Ti2 tetrahedra,  a cornercorner with one O(8)Sc2Ti2 tetrahedra,  a cornercorner with one O(10)Sc3Ti tetrahedra,  a cornercorner with one O(11)Sc3Ti tetrahedra,  a cornercorner with one O(9)Sc3Ti tetrahedra, corners with two equivalent O(12)Sc3Ti tetrahedra, corners with two equivalent O(4)Sc3Ti trigonal pyramids,  an edgeedge with one O(8)Sc2Ti2 tetrahedra,  an edgeedge with one O(10)Sc3Ti tetrahedra, and  an edgeedge with one O(9)Sc3Ti tetrahedra. In the seventh O site, O(7) is bonded to one Sc(3), one Sc(4), and two equivalent Ti(1) atoms to form OSc2Ti2 tetrahedra that share  a cornercorner with one O(10)Sc3Ti tetrahedra, corners with two equivalent O(12)Sc3Ti tetrahedra, corners with two equivalent O(9)Sc3Ti tetrahedra, corners with three equivalent O(11)Sc3Ti tetrahedra,  a cornercorner with one O(6)Sc2Ti2 trigonal pyramid,  an edgeedge with one O(7)Sc2Ti2 tetrahedra,  an edgeedge with one O(11)Sc3Ti tetrahedra, and  an edgeedge with one O(12)Sc3Ti tetrahedra. In the eighth O site, O(8) is bonded to one Sc(1), one Sc(2), and two equivalent Ti(3) atoms to form OSc2Ti2 tetrahedra that share  a cornercorner with one O(12)Sc3Ti tetrahedra,  a cornercorner with one O(9)Sc3Ti tetrahedra, corners with two equivalent O(10)Sc3Ti tetrahedra,  a cornercorner with one O(6)Sc2Ti2 trigonal pyramid, corners with three equivalent O(4)Sc3Ti trigonal pyramids,  an edgeedge with one O(8)Sc2Ti2 tetrahedra,  an edgeedge with one O(10)Sc3Ti tetrahedra,  an edgeedge with one O(6)Sc2Ti2 trigonal pyramid, and  an edgeedge with one O(4)Sc3Ti trigonal pyramid. In the ninth O site, O(9) is bonded to one Sc(2), one Sc(3), one Sc(4), and one Ti(2) atom to form distorted OSc3Ti tetrahedra that share  a cornercorner with one O(8)Sc2Ti2 tetrahedra,  a cornercorner with one O(11)Sc3Ti tetrahedra,  a cornercorner with one O(12)Sc3Ti tetrahedra, corners with two equivalent O(7)Sc2Ti2 tetrahedra, corners with two equivalent O(10)Sc3Ti tetrahedra,  a cornercorner with one O(6)Sc2Ti2 trigonal pyramid,  a cornercorner with one O(4)Sc3Ti trigonal pyramid,  an edgeedge with one O(11)Sc3Ti tetrahedra,  an edgeedge with one O(12)Sc3Ti tetrahedra, and  an edgeedge with one O(6)Sc2Ti2 trigonal pyramid. In the tenth O site, O(10) is bonded to one Sc(1), one Sc(2), one Sc(3), and one Ti(3) atom to form OSc3Ti tetrahedra that share  a cornercorner with one O(7)Sc2Ti2 tetrahedra,  a cornercorner with one O(11)Sc3Ti tetrahedra, corners with two equivalent O(8)Sc2Ti2 tetrahedra, corners with two equivalent O(9)Sc3Ti tetrahedra,  a cornercorner with one O(6)Sc2Ti2 trigonal pyramid, corners with two equivalent O(4)Sc3Ti trigonal pyramids,  an edgeedge with one O(8)Sc2Ti2 tetrahedra,  an edgeedge with one O(12)Sc3Ti tetrahedra,  an edgeedge with one O(6)Sc2Ti2 trigonal pyramid, and  an edgeedge with one O(4)Sc3Ti trigonal pyramid. In the eleventh O site, O(11) is bonded to one Sc(3), two equivalent Sc(4), and one Ti(1) atom to form OSc3Ti tetrahedra that share  a cornercorner with one O(10)Sc3Ti tetrahedra,  a cornercorner with one O(9)Sc3Ti tetrahedra, corners with two equivalent O(12)Sc3Ti tetrahedra, corners with three equivalent O(7)Sc2Ti2 tetrahedra,  a cornercorner with one O(6)Sc2Ti2 trigonal pyramid,  an edgeedge with one O(7)Sc2Ti2 tetrahedra,  an edgeedge with one O(11)Sc3Ti tetrahedra,  an edgeedge with one O(12)Sc3Ti tetrahedra, and  an edgeedge with one O(9)Sc3Ti tetrahedra. In the twelfth O site, O(12) is bonded to one Sc(2), one Sc(3), one Sc(4), and one Ti(1) atom to form distorted OSc3Ti tetrahedra that share  a cornercorner with one O(8)Sc2Ti2 tetrahedra,  a cornercorner with one O(9)Sc3Ti tetrahedra, corners with two equivalent O(7)Sc2Ti2 tetrahedra, corners with two equivalent O(11)Sc3Ti tetrahedra,  a cornercorner with one O(4)Sc3Ti trigonal pyramid, corners with two equivalent O(6)Sc2Ti2 trigonal pyramids,  an edgeedge with one O(7)Sc2Ti2 tetrahedra,  an edgeedge with one O(10)Sc3Ti tetrahedra,  an edgeedge with one O(11)Sc3Ti tetrahedra, and  an edgeedge with one O(9)Sc3Ti tetrahedra.