Ca2Y3Si3O13 crystallizes in the monoclinic P2_1/m space group. Ca(1) is bonded in a 9-coordinate geometry to one O(1), one O(2), one O(3), one O(4), one O(5), one O(6), one O(7), one O(8), and one O(9) atom. There are three inequivalent Y sites. In the first Y site, Y(1) is bonded to one O(10), one O(2), one O(4), two equivalent O(8), and two equivalent O(9) atoms to form distorted YO7 pentagonal bipyramids that share corners with three equivalent Y(2)O7 pentagonal bipyramids, corners with three equivalent Y(3)O7 pentagonal bipyramids,  a cornercorner with one Si(1)O4 tetrahedra, corners with three equivalent Si(3)O4 tetrahedra, and  an edgeedge with one Si(2)O4 tetrahedra. In the second Y site, Y(2) is bonded to one O(10), one O(5), one O(6), two equivalent O(7), and two equivalent O(8) atoms to form distorted YO7 pentagonal bipyramids that share corners with three equivalent Y(1)O7 pentagonal bipyramids, corners with three equivalent Y(3)O7 pentagonal bipyramids,  a cornercorner with one Si(3)O4 tetrahedra, corners with three equivalent Si(2)O4 tetrahedra, and  an edgeedge with one Si(1)O4 tetrahedra. In the third Y site, Y(3) is bonded to one O(1), one O(10), one O(3), two equivalent O(7), and two equivalent O(9) atoms to form distorted YO7 pentagonal bipyramids that share corners with three equivalent Y(1)O7 pentagonal bipyramids, corners with three equivalent Y(2)O7 pentagonal bipyramids,  a cornercorner with one Si(2)O4 tetrahedra, corners with three equivalent Si(1)O4 tetrahedra, and  an edgeedge with one Si(3)O4 tetrahedra. There are three inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(3), one O(4), and two equivalent O(7) atoms to form SiO4 tetrahedra that share  a cornercorner with one Y(1)O7 pentagonal bipyramid, corners with three equivalent Y(3)O7 pentagonal bipyramids, and  an edgeedge with one Y(2)O7 pentagonal bipyramid. In the second Si site, Si(2) is bonded to one O(1), one O(5), and two equivalent O(8) atoms to form SiO4 tetrahedra that share  a cornercorner with one Y(3)O7 pentagonal bipyramid, corners with three equivalent Y(2)O7 pentagonal bipyramids, and  an edgeedge with one Y(1)O7 pentagonal bipyramid. In the third Si site, Si(3) is bonded to one O(2), one O(6), and two equivalent O(9) atoms to form SiO4 tetrahedra that share  a cornercorner with one Y(2)O7 pentagonal bipyramid, corners with three equivalent Y(1)O7 pentagonal bipyramids, and  an edgeedge with one Y(3)O7 pentagonal bipyramid. There are ten inequivalent O sites. In the first O site, O(8) is bonded in a 1-coordinate geometry to one Ca(1), one Y(1), one Y(2), and one Si(2) atom. In the second O site, O(9) is bonded in a 4-coordinate geometry to one Ca(1), one Y(1), one Y(3), and one Si(3) atom. In the third O site, O(10) is bonded in a trigonal planar geometry to one Y(1), one Y(2), and one Y(3) atom. In the fourth O site, O(1) is bonded to two equivalent Ca(1), one Y(3), and one Si(2) atom to form distorted edge-sharing OCa2YSi tetrahedra. In the fifth O site, O(2) is bonded in a 4-coordinate geometry to two equivalent Ca(1), one Y(1), and one Si(3) atom. In the sixth O site, O(3) is bonded in a 4-coordinate geometry to two equivalent Ca(1), one Y(3), and one Si(1) atom. In the seventh O site, O(4) is bonded to two equivalent Ca(1), one Y(1), and one Si(1) atom to form distorted edge-sharing OCa2YSi tetrahedra. In the eighth O site, O(5) is bonded in a 4-coordinate geometry to two equivalent Ca(1), one Y(2), and one Si(2) atom. In the ninth O site, O(6) is bonded to two equivalent Ca(1), one Y(2), and one Si(3) atom to form distorted edge-sharing OCa2YSi tetrahedra. In the tenth O site, O(7) is bonded in a 1-coordinate geometry to one Ca(1), one Y(2), one Y(3), and one Si(1) atom.
Ca2Y3Si3O13 crystallizes in the monoclinic P2_1/m space group. Ca(1) is bonded in a 9-coordinate geometry to one O(1), one O(2), one O(3), one O(4), one O(5), one O(6), one O(7), one O(8), and one O(9) atom. The Ca(1)-O(1) bond length is 2.40 Å. The Ca(1)-O(2) bond length is 2.50 Å. The Ca(1)-O(3) bond length is 2.52 Å. The Ca(1)-O(4) bond length is 2.39 Å. The Ca(1)-O(5) bond length is 2.51 Å. The Ca(1)-O(6) bond length is 2.38 Å. The Ca(1)-O(7) bond length is 2.89 Å. The Ca(1)-O(8) bond length is 2.86 Å. The Ca(1)-O(9) bond length is 2.86 Å. There are three inequivalent Y sites. In the first Y site, Y(1) is bonded to one O(10), one O(2), one O(4), two equivalent O(8), and two equivalent O(9) atoms to form distorted YO7 pentagonal bipyramids that share corners with three equivalent Y(2)O7 pentagonal bipyramids, corners with three equivalent Y(3)O7 pentagonal bipyramids,  a cornercorner with one Si(1)O4 tetrahedra, corners with three equivalent Si(3)O4 tetrahedra, and  an edgeedge with one Si(2)O4 tetrahedra. The Y(1)-O(10) bond length is 2.31 Å. The Y(1)-O(2) bond length is 2.34 Å. The Y(1)-O(4) bond length is 2.53 Å. Both Y(1)-O(8) bond lengths are 2.43 Å. Both Y(1)-O(9) bond lengths are 2.30 Å. In the second Y site, Y(2) is bonded to one O(10), one O(5), one O(6), two equivalent O(7), and two equivalent O(8) atoms to form distorted YO7 pentagonal bipyramids that share corners with three equivalent Y(1)O7 pentagonal bipyramids, corners with three equivalent Y(3)O7 pentagonal bipyramids,  a cornercorner with one Si(3)O4 tetrahedra, corners with three equivalent Si(2)O4 tetrahedra, and  an edgeedge with one Si(1)O4 tetrahedra. The Y(2)-O(10) bond length is 2.31 Å. The Y(2)-O(5) bond length is 2.33 Å. The Y(2)-O(6) bond length is 2.52 Å. Both Y(2)-O(7) bond lengths are 2.42 Å. Both Y(2)-O(8) bond lengths are 2.31 Å. In the third Y site, Y(3) is bonded to one O(1), one O(10), one O(3), two equivalent O(7), and two equivalent O(9) atoms to form distorted YO7 pentagonal bipyramids that share corners with three equivalent Y(1)O7 pentagonal bipyramids, corners with three equivalent Y(2)O7 pentagonal bipyramids,  a cornercorner with one Si(2)O4 tetrahedra, corners with three equivalent Si(1)O4 tetrahedra, and  an edgeedge with one Si(3)O4 tetrahedra. The Y(3)-O(1) bond length is 2.53 Å. The Y(3)-O(10) bond length is 2.31 Å. The Y(3)-O(3) bond length is 2.32 Å. Both Y(3)-O(7) bond lengths are 2.31 Å. Both Y(3)-O(9) bond lengths are 2.43 Å. There are three inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(3), one O(4), and two equivalent O(7) atoms to form SiO4 tetrahedra that share  a cornercorner with one Y(1)O7 pentagonal bipyramid, corners with three equivalent Y(3)O7 pentagonal bipyramids, and  an edgeedge with one Y(2)O7 pentagonal bipyramid. The Si(1)-O(3) bond length is 1.64 Å. The Si(1)-O(4) bond length is 1.62 Å. Both Si(1)-O(7) bond lengths are 1.65 Å. In the second Si site, Si(2) is bonded to one O(1), one O(5), and two equivalent O(8) atoms to form SiO4 tetrahedra that share  a cornercorner with one Y(3)O7 pentagonal bipyramid, corners with three equivalent Y(2)O7 pentagonal bipyramids, and  an edgeedge with one Y(1)O7 pentagonal bipyramid. The Si(2)-O(1) bond length is 1.63 Å. The Si(2)-O(5) bond length is 1.64 Å. Both Si(2)-O(8) bond lengths are 1.65 Å. In the third Si site, Si(3) is bonded to one O(2), one O(6), and two equivalent O(9) atoms to form SiO4 tetrahedra that share  a cornercorner with one Y(2)O7 pentagonal bipyramid, corners with three equivalent Y(1)O7 pentagonal bipyramids, and  an edgeedge with one Y(3)O7 pentagonal bipyramid. The Si(3)-O(2) bond length is 1.64 Å. The Si(3)-O(6) bond length is 1.63 Å. Both Si(3)-O(9) bond lengths are 1.66 Å. There are ten inequivalent O sites. In the first O site, O(8) is bonded in a 1-coordinate geometry to one Ca(1), one Y(1), one Y(2), and one Si(2) atom. In the second O site, O(9) is bonded in a 4-coordinate geometry to one Ca(1), one Y(1), one Y(3), and one Si(3) atom. In the third O site, O(10) is bonded in a trigonal planar geometry to one Y(1), one Y(2), and one Y(3) atom. In the fourth O site, O(1) is bonded to two equivalent Ca(1), one Y(3), and one Si(2) atom to form distorted edge-sharing OCa2YSi tetrahedra. In the fifth O site, O(2) is bonded in a 4-coordinate geometry to two equivalent Ca(1), one Y(1), and one Si(3) atom. In the sixth O site, O(3) is bonded in a 4-coordinate geometry to two equivalent Ca(1), one Y(3), and one Si(1) atom. In the seventh O site, O(4) is bonded to two equivalent Ca(1), one Y(1), and one Si(1) atom to form distorted edge-sharing OCa2YSi tetrahedra. In the eighth O site, O(5) is bonded in a 4-coordinate geometry to two equivalent Ca(1), one Y(2), and one Si(2) atom. In the ninth O site, O(6) is bonded to two equivalent Ca(1), one Y(2), and one Si(3) atom to form distorted edge-sharing OCa2YSi tetrahedra. In the tenth O site, O(7) is bonded in a 1-coordinate geometry to one Ca(1), one Y(2), one Y(3), and one Si(1) atom.