CaSnSiO5 crystallizes in the monoclinic C2/c space group. Ca(1) is bonded in a 7-coordinate geometry to one O(3), two equivalent O(2), and four equivalent O(1) atoms. Sn(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form SnO6 octahedra that share corners with two equivalent Sn(1)O6 octahedra and corners with four equivalent Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles are 47°. Si(1) is bonded to two equivalent O(1) and two equivalent O(2) atoms to form SiO4 tetrahedra that share corners with four equivalent Sn(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 41-53°. There are three inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to two equivalent Ca(1), one Sn(1), and one Si(1) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Ca(1), one Sn(1), and one Si(1) atom. In the third O site, O(3) is bonded in a trigonal planar geometry to one Ca(1) and two equivalent Sn(1) atoms.
CaSnSiO5 crystallizes in the monoclinic C2/c space group. Ca(1) is bonded in a 7-coordinate geometry to one O(3), two equivalent O(2), and four equivalent O(1) atoms. The Ca(1)-O(3) bond length is 2.24 Å. Both Ca(1)-O(2) bond lengths are 2.43 Å. There are two shorter (2.48 Å) and two longer (2.77 Å) Ca(1)-O(1) bond lengths. Sn(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form SnO6 octahedra that share corners with two equivalent Sn(1)O6 octahedra and corners with four equivalent Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles are 47°. Both Sn(1)-O(1) bond lengths are 2.14 Å. Both Sn(1)-O(2) bond lengths are 2.12 Å. Both Sn(1)-O(3) bond lengths are 1.98 Å. Si(1) is bonded to two equivalent O(1) and two equivalent O(2) atoms to form SiO4 tetrahedra that share corners with four equivalent Sn(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 41-53°. Both Si(1)-O(1) bond lengths are 1.66 Å. Both Si(1)-O(2) bond lengths are 1.66 Å. There are three inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to two equivalent Ca(1), one Sn(1), and one Si(1) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Ca(1), one Sn(1), and one Si(1) atom. In the third O site, O(3) is bonded in a trigonal planar geometry to one Ca(1) and two equivalent Sn(1) atoms.