Ca2Mn3Si3H3O14 crystallizes in the monoclinic P2_1/m 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(3), one O(5), one O(6), two equivalent O(10), and two equivalent O(4) atoms. In the second Ca site, Ca(2) is bonded in a 7-coordinate geometry to one O(1), one O(7), one O(8), two equivalent O(10), and two equivalent O(2) atoms. There are three inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to two equivalent O(11), two equivalent O(2), and two equivalent O(7) atoms to form MnO6 octahedra that share corners with two equivalent Si(2)O4 tetrahedra, corners with two equivalent Si(3)O4 tetrahedra, and edges with two equivalent Mn(1)O6 octahedra. In the second Mn site, Mn(2) is bonded to two equivalent O(1), two equivalent O(10), and two equivalent O(6) atoms to form MnO6 octahedra that share corners with two equivalent Si(1)O4 tetrahedra, corners with two equivalent Si(3)O4 tetrahedra, and edges with two equivalent Mn(2)O6 octahedra. In the third Mn site, Mn(3) is bonded to two equivalent O(4), two equivalent O(5), and two equivalent O(9) atoms to form MnO6 octahedra that share corners with two equivalent Si(2)O4 tetrahedra, corners with two equivalent Si(3)O4 tetrahedra, and edges with two equivalent Mn(3)O6 octahedra. There are three inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(3), one O(8), and two equivalent O(10) atoms to form SiO4 tetrahedra that share corners with two equivalent Mn(2)O6 octahedra and  a cornercorner with one Si(2)O4 tetrahedra. The corner-sharing octahedral tilt angles are 55°. In the second Si site, Si(2) is bonded to one O(7), one O(8), and two equivalent O(4) atoms to form SiO4 tetrahedra that share corners with two equivalent Mn(1)O6 octahedra, corners with two equivalent Mn(3)O6 octahedra, and  a cornercorner with one Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 47-59°. In the third Si site, Si(3) is bonded to one O(5), one O(6), and two equivalent O(2) atoms to form SiO4 tetrahedra that share corners with two equivalent Mn(1)O6 octahedra, corners with two equivalent Mn(2)O6 octahedra, and corners with two equivalent Mn(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 48-58°. There are three inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one O(9) atom. In the second H site, H(2) is bonded in a single-bond geometry to one O(3) atom. In the third H site, H(3) is bonded in a linear geometry to one O(11) and one O(9) atom. There are eleven inequivalent O sites. In the first O site, O(1) is bonded in a trigonal non-coplanar geometry to one Ca(2) and two equivalent Mn(2) atoms. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one Ca(2), one Mn(1), and one Si(3) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Ca(1), one Si(1), and one H(2) atom. In the fourth O site, O(4) is bonded in a trigonal planar geometry to one Ca(1), one Mn(3), and one Si(2) atom. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to one Ca(1), two equivalent Mn(3), and one Si(3) atom. In the sixth O site, O(6) is bonded in a distorted rectangular see-saw-like geometry to one Ca(1), two equivalent Mn(2), and one Si(3) atom. In the seventh O site, O(7) is bonded in a distorted rectangular see-saw-like geometry to one Ca(2), two equivalent Mn(1), and one Si(2) atom. In the eighth O site, O(8) is bonded in a distorted bent 120 degrees geometry to one Ca(2), one Si(1), and one Si(2) atom. In the ninth O site, O(9) is bonded to two equivalent Mn(3), one H(1), and one H(3) atom to form distorted corner-sharing OMn2H2 tetrahedra. In the tenth O site, O(10) is bonded in a distorted rectangular see-saw-like geometry to one Ca(1), one Ca(2), one Mn(2), and one Si(1) atom. In the eleventh O site, O(11) is bonded in a distorted trigonal non-coplanar geometry to two equivalent Mn(1) and one H(3) atom.
Ca2Mn3Si3H3O14 crystallizes in the monoclinic P2_1/m 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(3), one O(5), one O(6), two equivalent O(10), and two equivalent O(4) atoms. The Ca(1)-O(3) bond length is 2.49 Å. The Ca(1)-O(5) bond length is 2.83 Å. The Ca(1)-O(6) bond length is 2.46 Å. Both Ca(1)-O(10) bond lengths are 2.47 Å. Both Ca(1)-O(4) bond lengths are 2.31 Å. In the second Ca site, Ca(2) is bonded in a 7-coordinate geometry to one O(1), one O(7), one O(8), two equivalent O(10), and two equivalent O(2) atoms. The Ca(2)-O(1) bond length is 2.28 Å. The Ca(2)-O(7) bond length is 2.35 Å. The Ca(2)-O(8) bond length is 2.75 Å. Both Ca(2)-O(10) bond lengths are 2.45 Å. Both Ca(2)-O(2) bond lengths are 2.40 Å. There are three inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to two equivalent O(11), two equivalent O(2), and two equivalent O(7) atoms to form MnO6 octahedra that share corners with two equivalent Si(2)O4 tetrahedra, corners with two equivalent Si(3)O4 tetrahedra, and edges with two equivalent Mn(1)O6 octahedra. Both Mn(1)-O(11) bond lengths are 1.97 Å. Both Mn(1)-O(2) bond lengths are 1.96 Å. Both Mn(1)-O(7) bond lengths are 2.29 Å. In the second Mn site, Mn(2) is bonded to two equivalent O(1), two equivalent O(10), and two equivalent O(6) atoms to form MnO6 octahedra that share corners with two equivalent Si(1)O4 tetrahedra, corners with two equivalent Si(3)O4 tetrahedra, and edges with two equivalent Mn(2)O6 octahedra. Both Mn(2)-O(1) bond lengths are 1.92 Å. Both Mn(2)-O(10) bond lengths are 2.19 Å. Both Mn(2)-O(6) bond lengths are 2.15 Å. In the third Mn site, Mn(3) is bonded to two equivalent O(4), two equivalent O(5), and two equivalent O(9) atoms to form MnO6 octahedra that share corners with two equivalent Si(2)O4 tetrahedra, corners with two equivalent Si(3)O4 tetrahedra, and edges with two equivalent Mn(3)O6 octahedra. Both Mn(3)-O(4) bond lengths are 1.93 Å. Both Mn(3)-O(5) bond lengths are 2.11 Å. Both Mn(3)-O(9) bond lengths are 2.05 Å. There are three inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(3), one O(8), and two equivalent O(10) atoms to form SiO4 tetrahedra that share corners with two equivalent Mn(2)O6 octahedra and  a cornercorner with one Si(2)O4 tetrahedra. The corner-sharing octahedral tilt angles are 55°. The Si(1)-O(3) bond length is 1.69 Å. The Si(1)-O(8) bond length is 1.67 Å. Both Si(1)-O(10) bond lengths are 1.64 Å. In the second Si site, Si(2) is bonded to one O(7), one O(8), and two equivalent O(4) atoms to form SiO4 tetrahedra that share corners with two equivalent Mn(1)O6 octahedra, corners with two equivalent Mn(3)O6 octahedra, and  a cornercorner with one Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 47-59°. The Si(2)-O(7) bond length is 1.63 Å. The Si(2)-O(8) bond length is 1.69 Å. Both Si(2)-O(4) bond lengths are 1.64 Å. In the third Si site, Si(3) is bonded to one O(5), one O(6), and two equivalent O(2) atoms to form SiO4 tetrahedra that share corners with two equivalent Mn(1)O6 octahedra, corners with two equivalent Mn(2)O6 octahedra, and corners with two equivalent Mn(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 48-58°. The Si(3)-O(5) bond length is 1.64 Å. The Si(3)-O(6) bond length is 1.66 Å. Both Si(3)-O(2) bond lengths are 1.65 Å. There are three inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one O(9) atom. The H(1)-O(9) bond length is 0.99 Å. In the second H site, H(2) is bonded in a single-bond geometry to one O(3) atom. The H(2)-O(3) bond length is 0.99 Å. In the third H site, H(3) is bonded in a linear geometry to one O(11) and one O(9) atom. The H(3)-O(11) bond length is 1.02 Å. The H(3)-O(9) bond length is 1.58 Å. There are eleven inequivalent O sites. In the first O site, O(1) is bonded in a trigonal non-coplanar geometry to one Ca(2) and two equivalent Mn(2) atoms. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one Ca(2), one Mn(1), and one Si(3) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Ca(1), one Si(1), and one H(2) atom. In the fourth O site, O(4) is bonded in a trigonal planar geometry to one Ca(1), one Mn(3), and one Si(2) atom. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to one Ca(1), two equivalent Mn(3), and one Si(3) atom. In the sixth O site, O(6) is bonded in a distorted rectangular see-saw-like geometry to one Ca(1), two equivalent Mn(2), and one Si(3) atom. In the seventh O site, O(7) is bonded in a distorted rectangular see-saw-like geometry to one Ca(2), two equivalent Mn(1), and one Si(2) atom. In the eighth O site, O(8) is bonded in a distorted bent 120 degrees geometry to one Ca(2), one Si(1), and one Si(2) atom. In the ninth O site, O(9) is bonded to two equivalent Mn(3), one H(1), and one H(3) atom to form distorted corner-sharing OMn2H2 tetrahedra. In the tenth O site, O(10) is bonded in a distorted rectangular see-saw-like geometry to one Ca(1), one Ca(2), one Mn(2), and one Si(1) atom. In the eleventh O site, O(11) is bonded in a distorted trigonal non-coplanar geometry to two equivalent Mn(1) and one H(3) atom.