CaMnSiO4 is Ilmenite-derived structured and crystallizes in the orthorhombic Pnma space group. Ca(1) is bonded to one O(2), one O(3), and four equivalent O(1) atoms to form distorted CaO6 octahedra that share corners with four equivalent Ca(1)O6 octahedra, corners with four equivalent Mn(1)O6 octahedra, corners with four equivalent Si(1)O4 tetrahedra, edges with two equivalent Mn(1)O6 octahedra, and  an edgeedge with one Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 57-66°. Mn(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form MnO6 octahedra that share corners with four equivalent Ca(1)O6 octahedra, corners with two equivalent Si(1)O4 tetrahedra, edges with two equivalent Ca(1)O6 octahedra, edges with two equivalent Mn(1)O6 octahedra, and edges with two equivalent Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 57-66°. Si(1) is bonded to one O(2), one O(3), and two equivalent O(1) atoms to form SiO4 tetrahedra that share corners with two equivalent Mn(1)O6 octahedra, corners with four equivalent Ca(1)O6 octahedra,  an edgeedge with one Ca(1)O6 octahedra, and edges with two equivalent Mn(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 49-63°. There are three inequivalent O sites. In the first O site, O(1) is bonded in a distorted rectangular see-saw-like geometry to two equivalent Ca(1), one Mn(1), and one Si(1) atom. In the second O site, O(2) is bonded in a distorted rectangular see-saw-like geometry to one Ca(1), two equivalent Mn(1), and one Si(1) atom. In the third O site, O(3) is bonded in a distorted rectangular see-saw-like geometry to one Ca(1), two equivalent Mn(1), and one Si(1) atom.
CaMnSiO4 is Ilmenite-derived structured and crystallizes in the orthorhombic Pnma space group. Ca(1) is bonded to one O(2), one O(3), and four equivalent O(1) atoms to form distorted CaO6 octahedra that share corners with four equivalent Ca(1)O6 octahedra, corners with four equivalent Mn(1)O6 octahedra, corners with four equivalent Si(1)O4 tetrahedra, edges with two equivalent Mn(1)O6 octahedra, and  an edgeedge with one Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 57-66°. The Ca(1)-O(2) bond length is 2.32 Å. The Ca(1)-O(3) bond length is 2.49 Å. There are two shorter (2.35 Å) and two longer (2.45 Å) Ca(1)-O(1) bond lengths. Mn(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form MnO6 octahedra that share corners with four equivalent Ca(1)O6 octahedra, corners with two equivalent Si(1)O4 tetrahedra, edges with two equivalent Ca(1)O6 octahedra, edges with two equivalent Mn(1)O6 octahedra, and edges with two equivalent Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 57-66°. Both Mn(1)-O(1) bond lengths are 2.24 Å. Both Mn(1)-O(2) bond lengths are 2.20 Å. Both Mn(1)-O(3) bond lengths are 2.29 Å. Si(1) is bonded to one O(2), one O(3), and two equivalent O(1) atoms to form SiO4 tetrahedra that share corners with two equivalent Mn(1)O6 octahedra, corners with four equivalent Ca(1)O6 octahedra,  an edgeedge with one Ca(1)O6 octahedra, and edges with two equivalent Mn(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 49-63°. The Si(1)-O(2) bond length is 1.68 Å. The Si(1)-O(3) bond length is 1.63 Å. Both Si(1)-O(1) bond lengths are 1.66 Å. There are three inequivalent O sites. In the first O site, O(1) is bonded in a distorted rectangular see-saw-like geometry to two equivalent Ca(1), one Mn(1), and one Si(1) atom. In the second O site, O(2) is bonded in a distorted rectangular see-saw-like geometry to one Ca(1), two equivalent Mn(1), and one Si(1) atom. In the third O site, O(3) is bonded in a distorted rectangular see-saw-like geometry to one Ca(1), two equivalent Mn(1), and one Si(1) atom.