Ca2Y3Si3O13 crystallizes in the monoclinic P2_1 space group. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 9-coordinate geometry to one O(1), one O(11), one O(2), one O(3), one O(4), one O(5), one O(6), one O(7), and one O(9) atom. In the second Ca site, Ca(2) is bonded in a 9-coordinate geometry to one O(1), one O(10), one O(12), one O(2), one O(3), one O(4), one O(5), one O(6), and one O(8) atom. There are three inequivalent Y sites. In the first Y site, Y(1) is bonded to one O(10), one O(11), one O(12), one O(13), one O(2), one O(4), and one O(9) atom 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(13), one O(5), one O(6), one O(7), one O(8), and one O(9) atom 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(11), one O(12), one O(13), one O(3), one O(7), and one O(8) atom 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), one O(7), and one O(8) atom 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(10), one O(5), and one O(9) atom 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(11), one O(12), one O(2), and one O(6) atom 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 thirteen inequivalent O sites. In the first O site, O(1) is bonded to one Ca(1), one Ca(2), one Y(3), and one Si(2) atom to form distorted edge-sharing OCa2YSi tetrahedra. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Ca(1), one Ca(2), one Y(1), and one Si(3) atom. In the third O site, O(3) is bonded in a 4-coordinate geometry to one Ca(1), one Ca(2), one Y(3), and one Si(1) atom. In the fourth O site, O(4) is bonded to one Ca(1), one Ca(2), one Y(1), and one Si(1) atom to form distorted edge-sharing OCa2YSi tetrahedra. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to one Ca(1), one Ca(2), one Y(2), and one Si(2) atom. In the sixth O site, O(6) is bonded to one Ca(1), one Ca(2), one Y(2), and one Si(3) atom to form distorted edge-sharing OCa2YSi tetrahedra. In the seventh 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. In the eighth O site, O(8) is bonded in a 3-coordinate geometry to one Ca(2), one Y(2), one Y(3), and one Si(1) atom. In the ninth O site, O(9) is bonded in a 1-coordinate geometry to one Ca(1), one Y(1), one Y(2), and one Si(2) atom. In the tenth O site, O(10) is bonded in a 3-coordinate geometry to one Ca(2), one Y(1), one Y(2), and one Si(2) atom. In the eleventh O site, O(11) is bonded in a 1-coordinate geometry to one Ca(1), one Y(1), one Y(3), and one Si(3) atom. In the twelfth O site, O(12) is bonded in a 3-coordinate geometry to one Ca(2), one Y(1), one Y(3), and one Si(3) atom. In the thirteenth O site, O(13) is bonded in a trigonal planar geometry to one Y(1), one Y(2), and one Y(3) atom.
Ca2Y3Si3O13 crystallizes in the monoclinic P2_1 space group. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 9-coordinate geometry to one O(1), one O(11), one O(2), one O(3), one O(4), one O(5), one O(6), one O(7), and one O(9) atom. The Ca(1)-O(1) bond length is 2.41 Å. The Ca(1)-O(11) bond length is 2.86 Å. The Ca(1)-O(2) bond length is 2.51 Å. The Ca(1)-O(3) bond length is 2.53 Å. The Ca(1)-O(4) bond length is 2.40 Å. The Ca(1)-O(5) bond length is 2.53 Å. The Ca(1)-O(6) bond length is 2.39 Å. The Ca(1)-O(7) bond length is 2.89 Å. The Ca(1)-O(9) bond length is 2.86 Å. In the second Ca site, Ca(2) is bonded in a 9-coordinate geometry to one O(1), one O(10), one O(12), one O(2), one O(3), one O(4), one O(5), one O(6), and one O(8) atom. The Ca(2)-O(1) bond length is 2.39 Å. The Ca(2)-O(10) bond length is 2.93 Å. The Ca(2)-O(12) bond length is 2.89 Å. The Ca(2)-O(2) bond length is 2.50 Å. The Ca(2)-O(3) bond length is 2.50 Å. The Ca(2)-O(4) bond length is 2.38 Å. The Ca(2)-O(5) bond length is 2.50 Å. The Ca(2)-O(6) bond length is 2.38 Å. The Ca(2)-O(8) bond length is 2.92 Å. There are three inequivalent Y sites. In the first Y site, Y(1) is bonded to one O(10), one O(11), one O(12), one O(13), one O(2), one O(4), and one O(9) atom 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 2.41 Å. The Y(1)-O(11) bond length is 2.31 Å. The Y(1)-O(12) bond length is 2.30 Å. The Y(1)-O(13) 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. The Y(1)-O(9) bond length is 2.42 Å. In the second Y site, Y(2) is bonded to one O(10), one O(13), one O(5), one O(6), one O(7), one O(8), and one O(9) atom 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(13) 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. The Y(2)-O(7) bond length is 2.41 Å. The Y(2)-O(8) bond length is 2.40 Å. The Y(2)-O(9) bond length is 2.31 Å. In the third Y site, Y(3) is bonded to one O(1), one O(11), one O(12), one O(13), one O(3), one O(7), and one O(8) atom 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(11) bond length is 2.43 Å. The Y(3)-O(12) bond length is 2.42 Å. The Y(3)-O(13) bond length is 2.31 Å. The Y(3)-O(3) bond length is 2.32 Å. The Y(3)-O(7) bond length is 2.32 Å. The Y(3)-O(8) bond length is 2.31 Å. There are three inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(3), one O(4), one O(7), and one O(8) atom 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. The Si(1)-O(7) bond length is 1.65 Å. The Si(1)-O(8) bond length is 1.65 Å. In the second Si site, Si(2) is bonded to one O(1), one O(10), one O(5), and one O(9) atom 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(10) bond length is 1.65 Å. The Si(2)-O(5) bond length is 1.64 Å. The Si(2)-O(9) bond length is 1.65 Å. In the third Si site, Si(3) is bonded to one O(11), one O(12), one O(2), and one O(6) atom 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(11) bond length is 1.65 Å. The Si(3)-O(12) bond length is 1.65 Å. The Si(3)-O(2) bond length is 1.64 Å. The Si(3)-O(6) bond length is 1.63 Å. There are thirteen inequivalent O sites. In the first O site, O(1) is bonded to one Ca(1), one Ca(2), one Y(3), and one Si(2) atom to form distorted edge-sharing OCa2YSi tetrahedra. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Ca(1), one Ca(2), one Y(1), and one Si(3) atom. In the third O site, O(3) is bonded in a 4-coordinate geometry to one Ca(1), one Ca(2), one Y(3), and one Si(1) atom. In the fourth O site, O(4) is bonded to one Ca(1), one Ca(2), one Y(1), and one Si(1) atom to form distorted edge-sharing OCa2YSi tetrahedra. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to one Ca(1), one Ca(2), one Y(2), and one Si(2) atom. In the sixth O site, O(6) is bonded to one Ca(1), one Ca(2), one Y(2), and one Si(3) atom to form distorted edge-sharing OCa2YSi tetrahedra. In the seventh 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. In the eighth O site, O(8) is bonded in a 3-coordinate geometry to one Ca(2), one Y(2), one Y(3), and one Si(1) atom. In the ninth O site, O(9) is bonded in a 1-coordinate geometry to one Ca(1), one Y(1), one Y(2), and one Si(2) atom. In the tenth O site, O(10) is bonded in a 3-coordinate geometry to one Ca(2), one Y(1), one Y(2), and one Si(2) atom. In the eleventh O site, O(11) is bonded in a 1-coordinate geometry to one Ca(1), one Y(1), one Y(3), and one Si(3) atom. In the twelfth O site, O(12) is bonded in a 3-coordinate geometry to one Ca(2), one Y(1), one Y(3), and one Si(3) atom. In the thirteenth O site, O(13) is bonded in a trigonal planar geometry to one Y(1), one Y(2), and one Y(3) atom.