CaMnSiHO5 is Esseneite-derived structured and crystallizes in the orthorhombic P2_12_12_1 space group. Ca(1) is bonded in a 8-coordinate geometry to one O(2), one O(3), two equivalent O(1), two equivalent O(4), and two equivalent O(5) atoms. Mn(1) is bonded to one O(1), one O(5), two equivalent O(2), and two equivalent O(3) atoms to form MnO6 octahedra that share corners with four equivalent Si(1)O4 tetrahedra and edges with two equivalent Mn(1)O6 octahedra. Si(1) is bonded to one O(1), one O(3), one O(4), and one O(5) atom to form SiO4 tetrahedra that share corners with four equivalent Mn(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 40-57°. H(1) is bonded in a linear geometry to one O(2) and one O(4) atom. There are five inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to two equivalent Ca(1), one Mn(1), and one Si(1) atom. In the second O site, O(2) is bonded to one Ca(1), two equivalent Mn(1), and one H(1) atom to form distorted OCaMn2H tetrahedra that share corners with two equivalent O(2)CaMn2H tetrahedra, corners with three equivalent O(3)CaMn2Si trigonal pyramids, and  an edgeedge with one O(3)CaMn2Si trigonal pyramid. In the third O site, O(3) is bonded to one Ca(1), two equivalent Mn(1), and one Si(1) atom to form distorted OCaMn2Si trigonal pyramids that share corners with three equivalent O(2)CaMn2H tetrahedra, corners with two equivalent O(3)CaMn2Si trigonal pyramids, and  an edgeedge with one O(2)CaMn2H tetrahedra. In the fourth O site, O(4) is bonded in a 2-coordinate geometry to two equivalent Ca(1), one Si(1), and one H(1) atom. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to two equivalent Ca(1), one Mn(1), and one Si(1) atom.
CaMnSiHO5 is Esseneite-derived structured and crystallizes in the orthorhombic P2_12_12_1 space group. Ca(1) is bonded in a 8-coordinate geometry to one O(2), one O(3), two equivalent O(1), two equivalent O(4), and two equivalent O(5) atoms. The Ca(1)-O(2) bond length is 2.32 Å. The Ca(1)-O(3) bond length is 2.43 Å. There is one shorter (2.49 Å) and one longer (2.54 Å) Ca(1)-O(1) bond length. There is one shorter (2.52 Å) and one longer (2.67 Å) Ca(1)-O(4) bond length. There is one shorter (2.51 Å) and one longer (2.60 Å) Ca(1)-O(5) bond length. Mn(1) is bonded to one O(1), one O(5), two equivalent O(2), and two equivalent O(3) atoms to form MnO6 octahedra that share corners with four equivalent Si(1)O4 tetrahedra and edges with two equivalent Mn(1)O6 octahedra. The Mn(1)-O(1) bond length is 2.06 Å. The Mn(1)-O(5) bond length is 2.07 Å. There is one shorter (1.89 Å) and one longer (1.91 Å) Mn(1)-O(2) bond length. There is one shorter (2.18 Å) and one longer (2.23 Å) Mn(1)-O(3) bond length. Si(1) is bonded to one O(1), one O(3), one O(4), and one O(5) atom to form SiO4 tetrahedra that share corners with four equivalent Mn(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 40-57°. The Si(1)-O(1) bond length is 1.66 Å. The Si(1)-O(3) bond length is 1.65 Å. The Si(1)-O(4) bond length is 1.67 Å. The Si(1)-O(5) bond length is 1.65 Å. H(1) is bonded in a linear geometry to one O(2) and one O(4) atom. The H(1)-O(2) bond length is 1.48 Å. The H(1)-O(4) bond length is 1.05 Å. There are five inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to two equivalent Ca(1), one Mn(1), and one Si(1) atom. In the second O site, O(2) is bonded to one Ca(1), two equivalent Mn(1), and one H(1) atom to form distorted OCaMn2H tetrahedra that share corners with two equivalent O(2)CaMn2H tetrahedra, corners with three equivalent O(3)CaMn2Si trigonal pyramids, and  an edgeedge with one O(3)CaMn2Si trigonal pyramid. In the third O site, O(3) is bonded to one Ca(1), two equivalent Mn(1), and one Si(1) atom to form distorted OCaMn2Si trigonal pyramids that share corners with three equivalent O(2)CaMn2H tetrahedra, corners with two equivalent O(3)CaMn2Si trigonal pyramids, and  an edgeedge with one O(2)CaMn2H tetrahedra. In the fourth O site, O(4) is bonded in a 2-coordinate geometry to two equivalent Ca(1), one Si(1), and one H(1) atom. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to two equivalent Ca(1), one Mn(1), and one Si(1) atom.