CaMnGeO4 is Spinel-derived structured and crystallizes in the orthorhombic Pnma space group. Ca(1) is bonded to one O(1), one O(2), and four equivalent O(3) atoms to form CaO6 octahedra that share corners with four equivalent Ca(1)O6 octahedra, corners with four equivalent Mn(1)O6 octahedra, corners with four equivalent Ge(1)O4 tetrahedra, edges with two equivalent Mn(1)O6 octahedra, and  an edgeedge with one Ge(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 56-62°. 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 Ge(1)O4 tetrahedra, edges with two equivalent Ca(1)O6 octahedra, edges with two equivalent Mn(1)O6 octahedra, and edges with two equivalent Ge(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 56-62°. Ge(1) is bonded to one O(1), one O(2), and two equivalent O(3) atoms to form GeO4 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 55-63°. There are three inequivalent O sites. In the first O site, O(1) is bonded to one Ca(1), two equivalent Mn(1), and one Ge(1) atom to form distorted corner-sharing OCaMn2Ge tetrahedra. In the second O site, O(2) is bonded in a rectangular see-saw-like geometry to one Ca(1), two equivalent Mn(1), and one Ge(1) atom. In the third O site, O(3) is bonded in a rectangular see-saw-like geometry to two equivalent Ca(1), one Mn(1), and one Ge(1) atom.
CaMnGeO4 is Spinel-derived structured and crystallizes in the orthorhombic Pnma space group. Ca(1) is bonded to one O(1), one O(2), and four equivalent O(3) atoms to form CaO6 octahedra that share corners with four equivalent Ca(1)O6 octahedra, corners with four equivalent Mn(1)O6 octahedra, corners with four equivalent Ge(1)O4 tetrahedra, edges with two equivalent Mn(1)O6 octahedra, and  an edgeedge with one Ge(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 56-62°. The Ca(1)-O(1) bond length is 2.46 Å. The Ca(1)-O(2) bond length is 2.33 Å. There are two shorter (2.33 Å) and two longer (2.46 Å) Ca(1)-O(3) 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 Ge(1)O4 tetrahedra, edges with two equivalent Ca(1)O6 octahedra, edges with two equivalent Mn(1)O6 octahedra, and edges with two equivalent Ge(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 56-62°. Both Mn(1)-O(1) bond lengths are 2.27 Å. Both Mn(1)-O(2) bond lengths are 2.22 Å. Both Mn(1)-O(3) bond lengths are 2.29 Å. Ge(1) is bonded to one O(1), one O(2), and two equivalent O(3) atoms to form GeO4 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 55-63°. The Ge(1)-O(1) bond length is 1.76 Å. The Ge(1)-O(2) bond length is 1.81 Å. Both Ge(1)-O(3) bond lengths are 1.79 Å. There are three inequivalent O sites. In the first O site, O(1) is bonded to one Ca(1), two equivalent Mn(1), and one Ge(1) atom to form distorted corner-sharing OCaMn2Ge tetrahedra. In the second O site, O(2) is bonded in a rectangular see-saw-like geometry to one Ca(1), two equivalent Mn(1), and one Ge(1) atom. In the third O site, O(3) is bonded in a rectangular see-saw-like geometry to two equivalent Ca(1), one Mn(1), and one Ge(1) atom.