BeMn2O4 is Ilmenite-like structured and crystallizes in the orthorhombic Pnma space group. Be(1) is bonded to one O(1), one O(2), and two equivalent O(3) atoms to form BeO4 tetrahedra that share corners with two equivalent Mn(1)O6 octahedra, corners with four equivalent Mn(2)O6 octahedra,  an edgeedge with one Mn(2)O6 octahedra, and edges with two equivalent Mn(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 58-63°. There are two inequivalent Mn sites. In the first Mn site, 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 Mn(2)O6 octahedra, corners with two equivalent Be(1)O4 tetrahedra, edges with two equivalent Mn(1)O6 octahedra, edges with two equivalent Mn(2)O6 octahedra, and edges with two equivalent Be(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 53-59°. In the second Mn site, Mn(2) is bonded to one O(1), one O(2), and four equivalent O(3) atoms to form MnO6 octahedra that share corners with four equivalent Mn(1)O6 octahedra, corners with four equivalent Mn(2)O6 octahedra, corners with four equivalent Be(1)O4 tetrahedra, edges with two equivalent Mn(1)O6 octahedra, and  an edgeedge with one Be(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 53-59°. There are three inequivalent O sites. In the first O site, O(1) is bonded in a rectangular see-saw-like geometry to one Be(1), one Mn(2), and two equivalent Mn(1) atoms. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Be(1), one Mn(2), and two equivalent Mn(1) atoms. In the third O site, O(3) is bonded in a distorted rectangular see-saw-like geometry to one Be(1), one Mn(1), and two equivalent Mn(2) atoms.
BeMn2O4 is Ilmenite-like structured and crystallizes in the orthorhombic Pnma space group. Be(1) is bonded to one O(1), one O(2), and two equivalent O(3) atoms to form BeO4 tetrahedra that share corners with two equivalent Mn(1)O6 octahedra, corners with four equivalent Mn(2)O6 octahedra,  an edgeedge with one Mn(2)O6 octahedra, and edges with two equivalent Mn(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 58-63°. The Be(1)-O(1) bond length is 1.71 Å. The Be(1)-O(2) bond length is 1.60 Å. Both Be(1)-O(3) bond lengths are 1.67 Å. There are two inequivalent Mn sites. In the first Mn site, 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 Mn(2)O6 octahedra, corners with two equivalent Be(1)O4 tetrahedra, edges with two equivalent Mn(1)O6 octahedra, edges with two equivalent Mn(2)O6 octahedra, and edges with two equivalent Be(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 53-59°. Both Mn(1)-O(1) bond lengths are 2.00 Å. Both Mn(1)-O(2) bond lengths are 2.04 Å. Both Mn(1)-O(3) bond lengths are 1.97 Å. In the second Mn site, Mn(2) is bonded to one O(1), one O(2), and four equivalent O(3) atoms to form MnO6 octahedra that share corners with four equivalent Mn(1)O6 octahedra, corners with four equivalent Mn(2)O6 octahedra, corners with four equivalent Be(1)O4 tetrahedra, edges with two equivalent Mn(1)O6 octahedra, and  an edgeedge with one Be(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 53-59°. The Mn(2)-O(1) bond length is 2.04 Å. The Mn(2)-O(2) bond length is 2.16 Å. There are two shorter (2.09 Å) and two longer (2.20 Å) Mn(2)-O(3) bond lengths. There are three inequivalent O sites. In the first O site, O(1) is bonded in a rectangular see-saw-like geometry to one Be(1), one Mn(2), and two equivalent Mn(1) atoms. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Be(1), one Mn(2), and two equivalent Mn(1) atoms. In the third O site, O(3) is bonded in a distorted rectangular see-saw-like geometry to one Be(1), one Mn(1), and two equivalent Mn(2) atoms.