Ca4ZrTi3(SiO5)4 crystallizes in the triclinic P-1 space group. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 7-coordinate geometry to one O(2), one O(4), one O(5), one O(6), one O(7), one O(8), and one O(9) atom. In the second Ca site, Ca(2) is bonded in a 7-coordinate geometry to one O(1), one O(10), one O(3), one O(5), one O(6), one O(7), and one O(8) atom. Zr(1) is bonded to two equivalent O(3), two equivalent O(5), and two equivalent O(9) atoms to form ZrO6 octahedra that share corners with two equivalent Ti(2)O6 octahedra, corners with two equivalent Si(1)O4 tetrahedra, and corners with two equivalent Si(2)O4 tetrahedra. The corner-sharing octahedral tilt angles are 44°. There are three inequivalent Ti sites. In the first Ti site, Ti(1) is bonded to two equivalent O(10), two equivalent O(4), and two equivalent O(6) atoms to form TiO6 octahedra that share corners with two equivalent Ti(3)O6 octahedra, corners with two equivalent Si(1)O4 tetrahedra, and corners with two equivalent Si(2)O4 tetrahedra. The corner-sharing octahedral tilt angles are 37°. In the second Ti site, Ti(2) is bonded to two equivalent O(1), two equivalent O(7), and two equivalent O(9) atoms to form TiO6 octahedra that share corners with two equivalent Zr(1)O6 octahedra, corners with two equivalent Si(1)O4 tetrahedra, and corners with two equivalent Si(2)O4 tetrahedra. The corner-sharing octahedral tilt angles are 44°. In the third Ti site, Ti(3) is bonded to two equivalent O(10), two equivalent O(2), and two equivalent O(8) atoms to form TiO6 octahedra that share corners with two equivalent Ti(1)O6 octahedra, corners with two equivalent Si(1)O4 tetrahedra, and corners with two equivalent Si(2)O4 tetrahedra. The corner-sharing octahedral tilt angles are 37°. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(2), one O(4), one O(5), and one O(7) atom to form SiO4 tetrahedra that share  a cornercorner with one Zr(1)O6 octahedra,  a cornercorner with one Ti(1)O6 octahedra,  a cornercorner with one Ti(2)O6 octahedra, and  a cornercorner with one Ti(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 36-55°. In the second Si site, Si(2) is bonded to one O(1), one O(3), one O(6), and one O(8) atom to form SiO4 tetrahedra that share  a cornercorner with one Zr(1)O6 octahedra,  a cornercorner with one Ti(1)O6 octahedra,  a cornercorner with one Ti(2)O6 octahedra, and  a cornercorner with one Ti(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 39-53°. There are ten inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Ca(2), one Ti(2), and one Si(2) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Ca(1), one Ti(3), and one Si(1) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Ca(2), one Zr(1), and one Si(2) atom. In the fourth O site, O(4) is bonded in a distorted T-shaped geometry to one Ca(1), one Ti(1), 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 Zr(1), and one Si(1) atom. In the sixth O site, O(6) is bonded in a 4-coordinate geometry to one Ca(1), one Ca(2), one Ti(1), and one Si(2) atom. In the seventh O site, O(7) is bonded in a 4-coordinate geometry to one Ca(1), one Ca(2), one Ti(2), and one Si(1) atom. In the eighth O site, O(8) is bonded in a 4-coordinate geometry to one Ca(1), one Ca(2), one Ti(3), and one Si(2) atom. In the ninth O site, O(9) is bonded in a trigonal planar geometry to one Ca(1), one Zr(1), and one Ti(2) atom. In the tenth O site, O(10) is bonded in a distorted trigonal planar geometry to one Ca(2), one Ti(1), and one Ti(3) atom.
Ca4ZrTi3(SiO5)4 crystallizes in the triclinic P-1 space group. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 7-coordinate geometry to one O(2), one O(4), one O(5), one O(6), one O(7), one O(8), and one O(9) atom. The Ca(1)-O(2) bond length is 2.40 Å. The Ca(1)-O(4) bond length is 2.42 Å. The Ca(1)-O(5) bond length is 2.71 Å. The Ca(1)-O(6) bond length is 2.46 Å. The Ca(1)-O(7) bond length is 2.69 Å. The Ca(1)-O(8) bond length is 2.50 Å. The Ca(1)-O(9) bond length is 2.24 Å. In the second Ca site, Ca(2) is bonded in a 7-coordinate geometry to one O(1), one O(10), one O(3), one O(5), one O(6), one O(7), and one O(8) atom. The Ca(2)-O(1) bond length is 2.49 Å. The Ca(2)-O(10) bond length is 2.29 Å. The Ca(2)-O(3) bond length is 2.48 Å. The Ca(2)-O(5) bond length is 2.49 Å. The Ca(2)-O(6) bond length is 2.71 Å. The Ca(2)-O(7) bond length is 2.41 Å. The Ca(2)-O(8) bond length is 2.64 Å. Zr(1) is bonded to two equivalent O(3), two equivalent O(5), and two equivalent O(9) atoms to form ZrO6 octahedra that share corners with two equivalent Ti(2)O6 octahedra, corners with two equivalent Si(1)O4 tetrahedra, and corners with two equivalent Si(2)O4 tetrahedra. The corner-sharing octahedral tilt angles are 44°. Both Zr(1)-O(3) bond lengths are 2.12 Å. Both Zr(1)-O(5) bond lengths are 2.15 Å. Both Zr(1)-O(9) bond lengths are 2.02 Å. There are three inequivalent Ti sites. In the first Ti site, Ti(1) is bonded to two equivalent O(10), two equivalent O(4), and two equivalent O(6) atoms to form TiO6 octahedra that share corners with two equivalent Ti(3)O6 octahedra, corners with two equivalent Si(1)O4 tetrahedra, and corners with two equivalent Si(2)O4 tetrahedra. The corner-sharing octahedral tilt angles are 37°. Both Ti(1)-O(10) bond lengths are 1.90 Å. Both Ti(1)-O(4) bond lengths are 2.01 Å. Both Ti(1)-O(6) bond lengths are 2.04 Å. In the second Ti site, Ti(2) is bonded to two equivalent O(1), two equivalent O(7), and two equivalent O(9) atoms to form TiO6 octahedra that share corners with two equivalent Zr(1)O6 octahedra, corners with two equivalent Si(1)O4 tetrahedra, and corners with two equivalent Si(2)O4 tetrahedra. The corner-sharing octahedral tilt angles are 44°. Both Ti(2)-O(1) bond lengths are 2.00 Å. Both Ti(2)-O(7) bond lengths are 2.08 Å. Both Ti(2)-O(9) bond lengths are 1.86 Å. In the third Ti site, Ti(3) is bonded to two equivalent O(10), two equivalent O(2), and two equivalent O(8) atoms to form TiO6 octahedra that share corners with two equivalent Ti(1)O6 octahedra, corners with two equivalent Si(1)O4 tetrahedra, and corners with two equivalent Si(2)O4 tetrahedra. The corner-sharing octahedral tilt angles are 37°. Both Ti(3)-O(10) bond lengths are 1.90 Å. Both Ti(3)-O(2) bond lengths are 2.01 Å. Both Ti(3)-O(8) bond lengths are 2.05 Å. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(2), one O(4), one O(5), and one O(7) atom to form SiO4 tetrahedra that share  a cornercorner with one Zr(1)O6 octahedra,  a cornercorner with one Ti(1)O6 octahedra,  a cornercorner with one Ti(2)O6 octahedra, and  a cornercorner with one Ti(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 36-55°. The Si(1)-O(2) bond length is 1.66 Å. The Si(1)-O(4) bond length is 1.65 Å. The Si(1)-O(5) bond length is 1.65 Å. The Si(1)-O(7) bond length is 1.65 Å. In the second Si site, Si(2) is bonded to one O(1), one O(3), one O(6), and one O(8) atom to form SiO4 tetrahedra that share  a cornercorner with one Zr(1)O6 octahedra,  a cornercorner with one Ti(1)O6 octahedra,  a cornercorner with one Ti(2)O6 octahedra, and  a cornercorner with one Ti(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 39-53°. The Si(2)-O(1) bond length is 1.65 Å. The Si(2)-O(3) bond length is 1.65 Å. The Si(2)-O(6) bond length is 1.66 Å. The Si(2)-O(8) bond length is 1.66 Å. There are ten inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Ca(2), one Ti(2), and one Si(2) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Ca(1), one Ti(3), and one Si(1) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Ca(2), one Zr(1), and one Si(2) atom. In the fourth O site, O(4) is bonded in a distorted T-shaped geometry to one Ca(1), one Ti(1), 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 Zr(1), and one Si(1) atom. In the sixth O site, O(6) is bonded in a 4-coordinate geometry to one Ca(1), one Ca(2), one Ti(1), and one Si(2) atom. In the seventh O site, O(7) is bonded in a 4-coordinate geometry to one Ca(1), one Ca(2), one Ti(2), and one Si(1) atom. In the eighth O site, O(8) is bonded in a 4-coordinate geometry to one Ca(1), one Ca(2), one Ti(3), and one Si(2) atom. In the ninth O site, O(9) is bonded in a trigonal planar geometry to one Ca(1), one Zr(1), and one Ti(2) atom. In the tenth O site, O(10) is bonded in a distorted trigonal planar geometry to one Ca(2), one Ti(1), and one Ti(3) atom.