CaScAlSiO6 is Esseneite-derived structured and crystallizes in the monoclinic C2 space group. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 8-coordinate geometry to two equivalent O(1), two equivalent O(4), two equivalent O(5), and two equivalent O(6) atoms. In the second Ca site, Ca(2) is bonded in a 8-coordinate geometry to two equivalent O(2), two equivalent O(3), two equivalent O(5), and two equivalent O(6) atoms. There are two inequivalent Sc sites. In the first Sc site, Sc(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form ScO6 octahedra that share corners with two equivalent Si(1)O4 tetrahedra, corners with four equivalent Al(1)O4 tetrahedra, and edges with two equivalent Sc(2)O6 octahedra. In the second Sc site, Sc(2) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(4) atoms to form ScO6 octahedra that share corners with two equivalent Al(1)O4 tetrahedra, corners with four equivalent Si(1)O4 tetrahedra, and edges with two equivalent Sc(1)O6 octahedra. Al(1) is bonded to one O(1), one O(3), one O(5), and one O(6) atom to form AlO4 tetrahedra that share  a cornercorner with one Sc(2)O6 octahedra, corners with two equivalent Sc(1)O6 octahedra, and corners with two equivalent Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 40-63°. Si(1) is bonded to one O(2), one O(4), one O(5), and one O(6) atom to form SiO4 tetrahedra that share  a cornercorner with one Sc(1)O6 octahedra, corners with two equivalent Sc(2)O6 octahedra, and corners with two equivalent Al(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 38-59°. There are six inequivalent O sites. In the first O site, O(1) is bonded to one Ca(1), one Sc(1), one Sc(2), and one Al(1) atom to form a mixture of distorted edge and corner-sharing OCaSc2Al tetrahedra. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Ca(2), one Sc(1), one Sc(2), and one Si(1) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Ca(2), one Sc(1), and one Al(1) atom. In the fourth O site, O(4) is bonded in a distorted T-shaped geometry to one Ca(1), one Sc(2), and one Si(1) atom. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to one Ca(1), one Ca(2), one Al(1), and one Si(1) atom. In the sixth O site, O(6) is bonded in a 2-coordinate geometry to one Ca(1), one Ca(2), one Al(1), and one Si(1) atom.
CaScAlSiO6 is Esseneite-derived structured and crystallizes in the monoclinic C2 space group. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 8-coordinate geometry to two equivalent O(1), two equivalent O(4), two equivalent O(5), and two equivalent O(6) atoms. Both Ca(1)-O(1) bond lengths are 2.41 Å. Both Ca(1)-O(4) bond lengths are 2.43 Å. Both Ca(1)-O(5) bond lengths are 2.59 Å. Both Ca(1)-O(6) bond lengths are 2.77 Å. In the second Ca site, Ca(2) is bonded in a 8-coordinate geometry to two equivalent O(2), two equivalent O(3), two equivalent O(5), and two equivalent O(6) atoms. Both Ca(2)-O(2) bond lengths are 2.51 Å. Both Ca(2)-O(3) bond lengths are 2.37 Å. Both Ca(2)-O(5) bond lengths are 2.71 Å. Both Ca(2)-O(6) bond lengths are 2.58 Å. There are two inequivalent Sc sites. In the first Sc site, Sc(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form ScO6 octahedra that share corners with two equivalent Si(1)O4 tetrahedra, corners with four equivalent Al(1)O4 tetrahedra, and edges with two equivalent Sc(2)O6 octahedra. Both Sc(1)-O(1) bond lengths are 2.22 Å. Both Sc(1)-O(2) bond lengths are 2.19 Å. Both Sc(1)-O(3) bond lengths are 2.00 Å. In the second Sc site, Sc(2) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(4) atoms to form ScO6 octahedra that share corners with two equivalent Al(1)O4 tetrahedra, corners with four equivalent Si(1)O4 tetrahedra, and edges with two equivalent Sc(1)O6 octahedra. Both Sc(2)-O(1) bond lengths are 2.07 Å. Both Sc(2)-O(2) bond lengths are 2.26 Å. Both Sc(2)-O(4) bond lengths are 2.07 Å. Al(1) is bonded to one O(1), one O(3), one O(5), and one O(6) atom to form AlO4 tetrahedra that share  a cornercorner with one Sc(2)O6 octahedra, corners with two equivalent Sc(1)O6 octahedra, and corners with two equivalent Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 40-63°. The Al(1)-O(1) bond length is 1.76 Å. The Al(1)-O(3) bond length is 1.74 Å. The Al(1)-O(5) bond length is 1.79 Å. The Al(1)-O(6) bond length is 1.81 Å. Si(1) is bonded to one O(2), one O(4), one O(5), and one O(6) atom to form SiO4 tetrahedra that share  a cornercorner with one Sc(1)O6 octahedra, corners with two equivalent Sc(2)O6 octahedra, and corners with two equivalent Al(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 38-59°. The Si(1)-O(2) bond length is 1.65 Å. The Si(1)-O(4) bond length is 1.63 Å. The Si(1)-O(5) bond length is 1.67 Å. The Si(1)-O(6) bond length is 1.66 Å. There are six inequivalent O sites. In the first O site, O(1) is bonded to one Ca(1), one Sc(1), one Sc(2), and one Al(1) atom to form a mixture of distorted edge and corner-sharing OCaSc2Al tetrahedra. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Ca(2), one Sc(1), one Sc(2), and one Si(1) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Ca(2), one Sc(1), and one Al(1) atom. In the fourth O site, O(4) is bonded in a distorted T-shaped geometry to one Ca(1), one Sc(2), and one Si(1) atom. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to one Ca(1), one Ca(2), one Al(1), and one Si(1) atom. In the sixth O site, O(6) is bonded in a 2-coordinate geometry to one Ca(1), one Ca(2), one Al(1), and one Si(1) atom.