MgBe2(CoO2)4 is Aluminum carbonitride-derived structured and crystallizes in the orthorhombic Imm2 space group. Mg(1) is bonded in a 4-coordinate geometry to two equivalent O(2) and two equivalent O(4) atoms. There are two inequivalent Be sites. In the first Be site, Be(1) is bonded to two equivalent O(2) and two equivalent O(3) atoms to form BeO4 tetrahedra that share corners with six equivalent Co(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 46-64°. In the second Be site, Be(2) is bonded to two equivalent O(1) and two equivalent O(4) atoms to form BeO4 tetrahedra that share corners with six equivalent Co(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 51-64°. There are two inequivalent Co sites. In the first Co site, Co(1) is bonded to one O(3), one O(4), two equivalent O(1), and two equivalent O(2) atoms to form CoO6 octahedra that share corners with three equivalent Be(1)O4 tetrahedra, corners with three equivalent Be(2)O4 tetrahedra, and edges with two equivalent Co(1)O6 octahedra. In the second Co site, Co(2) is bonded in a 5-coordinate geometry to one O(1), two equivalent O(3), and two equivalent O(4) atoms. There are four inequivalent O sites. In the first O site, O(1) is bonded in a distorted rectangular see-saw-like geometry to one Be(2), one Co(2), and two equivalent Co(1) atoms. In the second O site, O(2) is bonded to one Mg(1), one Be(1), and two equivalent Co(1) atoms to form distorted OMgBeCo2 tetrahedra that share corners with four equivalent O(3)BeCo3 tetrahedra and edges with two equivalent O(2)MgBeCo2 tetrahedra. In the third O site, O(3) is bonded to one Be(1), one Co(1), and two equivalent Co(2) atoms to form distorted OBeCo3 tetrahedra that share  a cornercorner with one O(3)BeCo3 tetrahedra, corners with four equivalent O(2)MgBeCo2 tetrahedra, and  an edgeedge with one O(3)BeCo3 tetrahedra. In the fourth O site, O(4) is bonded in a 5-coordinate geometry to one Mg(1), one Be(2), one Co(1), and two equivalent Co(2) atoms.
MgBe2(CoO2)4 is Aluminum carbonitride-derived structured and crystallizes in the orthorhombic Imm2 space group. Mg(1) is bonded in a 4-coordinate geometry to two equivalent O(2) and two equivalent O(4) atoms. Both Mg(1)-O(2) bond lengths are 1.88 Å. Both Mg(1)-O(4) bond lengths are 1.95 Å. There are two inequivalent Be sites. In the first Be site, Be(1) is bonded to two equivalent O(2) and two equivalent O(3) atoms to form BeO4 tetrahedra that share corners with six equivalent Co(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 46-64°. Both Be(1)-O(2) bond lengths are 1.78 Å. Both Be(1)-O(3) bond lengths are 1.64 Å. In the second Be site, Be(2) is bonded to two equivalent O(1) and two equivalent O(4) atoms to form BeO4 tetrahedra that share corners with six equivalent Co(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 51-64°. Both Be(2)-O(1) bond lengths are 1.77 Å. Both Be(2)-O(4) bond lengths are 1.70 Å. There are two inequivalent Co sites. In the first Co site, Co(1) is bonded to one O(3), one O(4), two equivalent O(1), and two equivalent O(2) atoms to form CoO6 octahedra that share corners with three equivalent Be(1)O4 tetrahedra, corners with three equivalent Be(2)O4 tetrahedra, and edges with two equivalent Co(1)O6 octahedra. The Co(1)-O(3) bond length is 2.30 Å. The Co(1)-O(4) bond length is 2.28 Å. Both Co(1)-O(1) bond lengths are 2.10 Å. Both Co(1)-O(2) bond lengths are 2.01 Å. In the second Co site, Co(2) is bonded in a 5-coordinate geometry to one O(1), two equivalent O(3), and two equivalent O(4) atoms. The Co(2)-O(1) bond length is 1.88 Å. Both Co(2)-O(3) bond lengths are 1.97 Å. Both Co(2)-O(4) bond lengths are 2.12 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded in a distorted rectangular see-saw-like geometry to one Be(2), one Co(2), and two equivalent Co(1) atoms. In the second O site, O(2) is bonded to one Mg(1), one Be(1), and two equivalent Co(1) atoms to form distorted OMgBeCo2 tetrahedra that share corners with four equivalent O(3)BeCo3 tetrahedra and edges with two equivalent O(2)MgBeCo2 tetrahedra. In the third O site, O(3) is bonded to one Be(1), one Co(1), and two equivalent Co(2) atoms to form distorted OBeCo3 tetrahedra that share  a cornercorner with one O(3)BeCo3 tetrahedra, corners with four equivalent O(2)MgBeCo2 tetrahedra, and  an edgeedge with one O(3)BeCo3 tetrahedra. In the fourth O site, O(4) is bonded in a 5-coordinate geometry to one Mg(1), one Be(2), one Co(1), and two equivalent Co(2) atoms.