Ca3Si3(HO5)2 crystallizes in the triclinic P-1 space group. There are three inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 7-coordinate geometry to one O(1), one O(10), one O(4), one O(5), one O(6), one O(7), and one O(8) atom. In the second Ca site, Ca(2) is bonded in a 6-coordinate geometry to one O(3), one O(5), one O(6), one O(9), and two equivalent O(10) atoms. In the third Ca site, Ca(3) is bonded in a 6-coordinate geometry to one O(1), one O(2), one O(5), one O(9), and two equivalent O(3) atoms. There are three inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form corner-sharing SiO4 tetrahedra. In the second Si site, Si(2) is bonded to one O(4), one O(5), one O(6), and one O(7) atom to form corner-sharing SiO4 tetrahedra. In the third Si site, Si(3) is bonded to one O(10), one O(7), one O(8), and one O(9) atom to form corner-sharing SiO4 tetrahedra. There are two inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one O(2) atom. In the second H site, H(2) is bonded in a distorted linear geometry to one O(6) and one O(8) atom. There are ten inequivalent O sites. In the first O site, O(9) is bonded in a distorted trigonal planar geometry to one Ca(2), one Ca(3), and one Si(3) atom. In the second O site, O(10) is bonded to one Ca(1), two equivalent Ca(2), and one Si(3) atom to form a mixture of distorted edge and corner-sharing OCa3Si tetrahedra. In the third O site, O(1) is bonded in a 3-coordinate geometry to one Ca(1), one Ca(3), and one Si(1) atom. In the fourth O site, O(2) is bonded in a 3-coordinate geometry to one Ca(3), one Si(1), and one H(1) atom. In the fifth O site, O(3) is bonded to one Ca(2), two equivalent Ca(3), and one Si(1) atom to form a mixture of distorted edge and corner-sharing OCa3Si tetrahedra. In the sixth O site, O(4) is bonded in a distorted bent 150 degrees geometry to one Ca(1), one Si(1), and one Si(2) atom. In the seventh O site, O(5) is bonded in a 4-coordinate geometry to one Ca(1), one Ca(2), one Ca(3), and one Si(2) atom. In the eighth O site, O(6) is bonded in a 4-coordinate geometry to one Ca(1), one Ca(2), one Si(2), and one H(2) atom. In the ninth O site, O(7) is bonded in a distorted bent 120 degrees geometry to one Ca(1), one Si(2), and one Si(3) atom. In the tenth O site, O(8) is bonded in a 1-coordinate geometry to one Ca(1), one Si(3), and one H(2) atom.
Ca3Si3(HO5)2 crystallizes in the triclinic P-1 space group. There are three inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 7-coordinate geometry to one O(1), one O(10), one O(4), one O(5), one O(6), one O(7), and one O(8) atom. The Ca(1)-O(1) bond length is 2.32 Å. The Ca(1)-O(10) bond length is 2.33 Å. The Ca(1)-O(4) bond length is 2.62 Å. The Ca(1)-O(5) bond length is 2.42 Å. The Ca(1)-O(6) bond length is 2.41 Å. The Ca(1)-O(7) bond length is 2.73 Å. The Ca(1)-O(8) bond length is 2.52 Å. In the second Ca site, Ca(2) is bonded in a 6-coordinate geometry to one O(3), one O(5), one O(6), one O(9), and two equivalent O(10) atoms. The Ca(2)-O(3) bond length is 2.41 Å. The Ca(2)-O(5) bond length is 2.39 Å. The Ca(2)-O(6) bond length is 2.45 Å. The Ca(2)-O(9) bond length is 2.32 Å. There is one shorter (2.41 Å) and one longer (2.56 Å) Ca(2)-O(10) bond length. In the third Ca site, Ca(3) is bonded in a 6-coordinate geometry to one O(1), one O(2), one O(5), one O(9), and two equivalent O(3) atoms. The Ca(3)-O(1) bond length is 2.30 Å. The Ca(3)-O(2) bond length is 2.40 Å. The Ca(3)-O(5) bond length is 2.59 Å. The Ca(3)-O(9) bond length is 2.35 Å. There is one shorter (2.40 Å) and one longer (2.43 Å) Ca(3)-O(3) bond length. There are three inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form corner-sharing SiO4 tetrahedra. The Si(1)-O(1) bond length is 1.62 Å. The Si(1)-O(2) bond length is 1.67 Å. The Si(1)-O(3) bond length is 1.63 Å. The Si(1)-O(4) bond length is 1.66 Å. In the second Si site, Si(2) is bonded to one O(4), one O(5), one O(6), and one O(7) atom to form corner-sharing SiO4 tetrahedra. The Si(2)-O(4) bond length is 1.65 Å. The Si(2)-O(5) bond length is 1.62 Å. The Si(2)-O(6) bond length is 1.64 Å. The Si(2)-O(7) bond length is 1.69 Å. In the third Si site, Si(3) is bonded to one O(10), one O(7), one O(8), and one O(9) atom to form corner-sharing SiO4 tetrahedra. The Si(3)-O(10) bond length is 1.63 Å. The Si(3)-O(7) bond length is 1.69 Å. The Si(3)-O(8) bond length is 1.70 Å. The Si(3)-O(9) bond length is 1.60 Å. There are two inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one O(2) atom. The H(1)-O(2) bond length is 1.00 Å. In the second H site, H(2) is bonded in a distorted linear geometry to one O(6) and one O(8) atom. The H(2)-O(6) bond length is 1.53 Å. The H(2)-O(8) bond length is 1.04 Å. There are ten inequivalent O sites. In the first O site, O(9) is bonded in a distorted trigonal planar geometry to one Ca(2), one Ca(3), and one Si(3) atom. In the second O site, O(10) is bonded to one Ca(1), two equivalent Ca(2), and one Si(3) atom to form a mixture of distorted edge and corner-sharing OCa3Si tetrahedra. In the third O site, O(1) is bonded in a 3-coordinate geometry to one Ca(1), one Ca(3), and one Si(1) atom. In the fourth O site, O(2) is bonded in a 3-coordinate geometry to one Ca(3), one Si(1), and one H(1) atom. In the fifth O site, O(3) is bonded to one Ca(2), two equivalent Ca(3), and one Si(1) atom to form a mixture of distorted edge and corner-sharing OCa3Si tetrahedra. In the sixth O site, O(4) is bonded in a distorted bent 150 degrees geometry to one Ca(1), one Si(1), and one Si(2) atom. In the seventh O site, O(5) is bonded in a 4-coordinate geometry to one Ca(1), one Ca(2), one Ca(3), and one Si(2) atom. In the eighth O site, O(6) is bonded in a 4-coordinate geometry to one Ca(1), one Ca(2), one Si(2), and one H(2) atom. In the ninth O site, O(7) is bonded in a distorted bent 120 degrees geometry to one Ca(1), one Si(2), and one Si(3) atom. In the tenth O site, O(8) is bonded in a 1-coordinate geometry to one Ca(1), one Si(3), and one H(2) atom.