Ca3(Si3O11)2 crystallizes in the triclinic P1 space group. There are three inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 5-coordinate geometry to one O(11), one O(12), one O(14), one O(18), one O(19), and one O(4) atom. In the second Ca site, Ca(2) is bonded to one O(11), one O(12), one O(15), one O(22), and one O(5) atom to form distorted CaO5 trigonal bipyramids that share  a cornercorner with one Si(2)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra,  a cornercorner with one Si(4)O4 tetrahedra, and  a cornercorner with one Si(6)O4 tetrahedra. In the third Ca site, Ca(3) is bonded in a 4-coordinate geometry to one O(11), one O(15), one O(22), one O(4), and one O(5) atom. There are six inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), one O(2), one O(4), and one O(7) atom to form corner-sharing SiO4 tetrahedra. In the second Si site, Si(2) is bonded to one O(1), one O(3), one O(5), and one O(6) atom to form SiO4 tetrahedra that share  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra,  a cornercorner with one Si(6)O4 tetrahedra, and  a cornercorner with one Ca(2)O5 trigonal bipyramid. In the third Si site, Si(3) is bonded to one O(11), one O(6), one O(8), and one O(9) atom to form SiO4 tetrahedra that share  a cornercorner with one Si(2)O4 tetrahedra,  a cornercorner with one Si(4)O4 tetrahedra,  a cornercorner with one Si(6)O4 tetrahedra, and  a cornercorner with one Ca(2)O5 trigonal bipyramid. In the fourth Si site, Si(4) is bonded to one O(10), one O(12), one O(7), and one O(8) atom to form SiO4 tetrahedra that share  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra,  a cornercorner with one Si(5)O4 tetrahedra, and  a cornercorner with one Ca(2)O5 trigonal bipyramid. In the fifth Si site, Si(5) is bonded to one O(10), one O(13), one O(14), and one O(2) atom to form corner-sharing SiO4 tetrahedra. In the sixth Si site, Si(6) is bonded to one O(13), one O(15), one O(3), and one O(9) atom to form SiO4 tetrahedra that share  a cornercorner with one Si(2)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra,  a cornercorner with one Si(5)O4 tetrahedra, and  a cornercorner with one Ca(2)O5 trigonal bipyramid. There are twenty-two inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one Si(1) and one Si(2) atom. In the second O site, O(2) is bonded in a bent 150 degrees geometry to one Si(1) and one Si(5) atom. In the third O site, O(3) is bonded in a bent 150 degrees geometry to one Si(2) and one Si(6) atom. In the fourth O site, O(4) is bonded in a trigonal planar geometry to one Ca(1), one Ca(3), and one Si(1) atom. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to one Ca(2), one Ca(3), and one Si(2) atom. In the sixth O site, O(6) is bonded in a bent 150 degrees geometry to one Si(2) and one Si(3) atom. In the seventh O site, O(7) is bonded in a bent 150 degrees geometry to one Si(1) and one Si(4) atom. In the eighth O site, O(8) is bonded in a bent 150 degrees geometry to one Si(3) and one Si(4) atom. In the ninth O site, O(9) is bonded in a bent 150 degrees geometry to one Si(3) and one Si(6) atom. In the tenth O site, O(10) is bonded in a bent 120 degrees geometry to one Si(4) and one Si(5) atom. In the eleventh O site, O(11) is bonded in a distorted tetrahedral geometry to one Ca(1), one Ca(2), one Ca(3), and one Si(3) atom. In the twelfth O site, O(12) is bonded in a distorted trigonal planar geometry to one Ca(1), one Ca(2), and one Si(4) atom. In the thirteenth O site, O(13) is bonded in a bent 150 degrees geometry to one Si(5) and one Si(6) atom. In the fourteenth O site, O(14) is bonded in a bent 120 degrees geometry to one Ca(1) and one Si(5) atom. In the fifteenth O site, O(15) is bonded in a distorted trigonal planar geometry to one Ca(2), one Ca(3), and one Si(6) atom. In the sixteenth O site, O(16) is bonded in a single-bond geometry to one O(21) atom. In the seventeenth O site, O(17) is bonded in a single-bond geometry to one O(19) atom. In the eighteenth O site, O(18) is bonded in a bent 120 degrees geometry to one Ca(1) and one O(21) atom. In the nineteenth O site, O(19) is bonded in a bent 120 degrees geometry to one Ca(1) and one O(17) atom. In the twentieth O site, O(20) is bonded in a single-bond geometry to one O(22) atom. In the twenty-first O site, O(21) is bonded in a bent 120 degrees geometry to one O(16) and one O(18) atom. In the twenty-second O site, O(22) is bonded in a 3-coordinate geometry to one Ca(2), one Ca(3), and one O(20) atom.
Ca3(Si3O11)2 crystallizes in the triclinic P1 space group. There are three inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 5-coordinate geometry to one O(11), one O(12), one O(14), one O(18), one O(19), and one O(4) atom. The Ca(1)-O(11) bond length is 2.49 Å. The Ca(1)-O(12) bond length is 2.33 Å. The Ca(1)-O(14) bond length is 2.24 Å. The Ca(1)-O(18) bond length is 2.55 Å. The Ca(1)-O(19) bond length is 3.05 Å. The Ca(1)-O(4) bond length is 2.30 Å. In the second Ca site, Ca(2) is bonded to one O(11), one O(12), one O(15), one O(22), and one O(5) atom to form distorted CaO5 trigonal bipyramids that share  a cornercorner with one Si(2)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra,  a cornercorner with one Si(4)O4 tetrahedra, and  a cornercorner with one Si(6)O4 tetrahedra. The Ca(2)-O(11) bond length is 2.36 Å. The Ca(2)-O(12) bond length is 2.25 Å. The Ca(2)-O(15) bond length is 2.22 Å. The Ca(2)-O(22) bond length is 2.85 Å. The Ca(2)-O(5) bond length is 2.24 Å. In the third Ca site, Ca(3) is bonded in a 4-coordinate geometry to one O(11), one O(15), one O(22), one O(4), and one O(5) atom. The Ca(3)-O(11) bond length is 2.38 Å. The Ca(3)-O(15) bond length is 2.28 Å. The Ca(3)-O(22) bond length is 3.08 Å. The Ca(3)-O(4) bond length is 2.23 Å. The Ca(3)-O(5) bond length is 2.26 Å. There are six inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), one O(2), one O(4), and one O(7) atom to form corner-sharing SiO4 tetrahedra. The Si(1)-O(1) bond length is 1.65 Å. The Si(1)-O(2) 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 1.63 Å. In the second Si site, Si(2) is bonded to one O(1), one O(3), one O(5), and one O(6) atom to form SiO4 tetrahedra that share  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra,  a cornercorner with one Si(6)O4 tetrahedra, and  a cornercorner with one Ca(2)O5 trigonal bipyramid. The Si(2)-O(1) bond length is 1.62 Å. The Si(2)-O(3) bond length is 1.65 Å. The Si(2)-O(5) bond length is 1.61 Å. The Si(2)-O(6) bond length is 1.65 Å. In the third Si site, Si(3) is bonded to one O(11), one O(6), one O(8), and one O(9) atom to form SiO4 tetrahedra that share  a cornercorner with one Si(2)O4 tetrahedra,  a cornercorner with one Si(4)O4 tetrahedra,  a cornercorner with one Si(6)O4 tetrahedra, and  a cornercorner with one Ca(2)O5 trigonal bipyramid. The Si(3)-O(11) bond length is 1.63 Å. The Si(3)-O(6) bond length is 1.64 Å. The Si(3)-O(8) bond length is 1.64 Å. The Si(3)-O(9) bond length is 1.63 Å. In the fourth Si site, Si(4) is bonded to one O(10), one O(12), one O(7), and one O(8) atom to form SiO4 tetrahedra that share  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra,  a cornercorner with one Si(5)O4 tetrahedra, and  a cornercorner with one Ca(2)O5 trigonal bipyramid. The Si(4)-O(10) bond length is 1.64 Å. The Si(4)-O(12) bond length is 1.62 Å. The Si(4)-O(7) bond length is 1.63 Å. The Si(4)-O(8) bond length is 1.68 Å. In the fifth Si site, Si(5) is bonded to one O(10), one O(13), one O(14), and one O(2) atom to form corner-sharing SiO4 tetrahedra. The Si(5)-O(10) bond length is 1.65 Å. The Si(5)-O(13) bond length is 1.63 Å. The Si(5)-O(14) bond length is 1.62 Å. The Si(5)-O(2) bond length is 1.65 Å. In the sixth Si site, Si(6) is bonded to one O(13), one O(15), one O(3), and one O(9) atom to form SiO4 tetrahedra that share  a cornercorner with one Si(2)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra,  a cornercorner with one Si(5)O4 tetrahedra, and  a cornercorner with one Ca(2)O5 trigonal bipyramid. The Si(6)-O(13) bond length is 1.62 Å. The Si(6)-O(15) bond length is 1.61 Å. The Si(6)-O(3) bond length is 1.65 Å. The Si(6)-O(9) bond length is 1.65 Å. There are twenty-two inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one Si(1) and one Si(2) atom. In the second O site, O(2) is bonded in a bent 150 degrees geometry to one Si(1) and one Si(5) atom. In the third O site, O(3) is bonded in a bent 150 degrees geometry to one Si(2) and one Si(6) atom. In the fourth O site, O(4) is bonded in a trigonal planar geometry to one Ca(1), one Ca(3), and one Si(1) atom. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to one Ca(2), one Ca(3), and one Si(2) atom. In the sixth O site, O(6) is bonded in a bent 150 degrees geometry to one Si(2) and one Si(3) atom. In the seventh O site, O(7) is bonded in a bent 150 degrees geometry to one Si(1) and one Si(4) atom. In the eighth O site, O(8) is bonded in a bent 150 degrees geometry to one Si(3) and one Si(4) atom. In the ninth O site, O(9) is bonded in a bent 150 degrees geometry to one Si(3) and one Si(6) atom. In the tenth O site, O(10) is bonded in a bent 120 degrees geometry to one Si(4) and one Si(5) atom. In the eleventh O site, O(11) is bonded in a distorted tetrahedral geometry to one Ca(1), one Ca(2), one Ca(3), and one Si(3) atom. In the twelfth O site, O(12) is bonded in a distorted trigonal planar geometry to one Ca(1), one Ca(2), and one Si(4) atom. In the thirteenth O site, O(13) is bonded in a bent 150 degrees geometry to one Si(5) and one Si(6) atom. In the fourteenth O site, O(14) is bonded in a bent 120 degrees geometry to one Ca(1) and one Si(5) atom. In the fifteenth O site, O(15) is bonded in a distorted trigonal planar geometry to one Ca(2), one Ca(3), and one Si(6) atom. In the sixteenth O site, O(16) is bonded in a single-bond geometry to one O(21) atom. The O(16)-O(21) bond length is 1.29 Å. In the seventeenth O site, O(17) is bonded in a single-bond geometry to one O(19) atom. The O(17)-O(19) bond length is 1.23 Å. In the eighteenth O site, O(18) is bonded in a bent 120 degrees geometry to one Ca(1) and one O(21) atom. The O(18)-O(21) bond length is 1.31 Å. In the nineteenth O site, O(19) is bonded in a bent 120 degrees geometry to one Ca(1) and one O(17) atom. In the twentieth O site, O(20) is bonded in a single-bond geometry to one O(22) atom. The O(20)-O(22) bond length is 1.23 Å. In the twenty-first O site, O(21) is bonded in a bent 120 degrees geometry to one O(16) and one O(18) atom. In the twenty-second O site, O(22) is bonded in a 3-coordinate geometry to one Ca(2), one Ca(3), and one O(20) atom.