MgBe2(CoO2)4 crystallizes in the cubic F-43m space group. Mg(1) is bonded to four equivalent Co(1) and four equivalent O(2) atoms to form distorted MgCo4O4 tetrahedra that share corners with four equivalent Be(1)O4 tetrahedra. There are two inequivalent Be sites. In the first Be site, Be(1) is bonded to four equivalent O(2) atoms to form BeO4 tetrahedra that share corners with four equivalent Mg(1)Co4O4 tetrahedra. In the second Be site, Be(2) is bonded in a tetrahedral geometry to four equivalent O(1) atoms. Co(1) is bonded in a 7-coordinate geometry to one Mg(1), three equivalent O(1), and three equivalent O(2) atoms. There are two inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to one Be(2) and three equivalent Co(1) atoms. In the second O site, O(2) is bonded in a distorted linear geometry to one Mg(1), one Be(1), and three equivalent Co(1) atoms.
MgBe2(CoO2)4 crystallizes in the cubic F-43m space group. Mg(1) is bonded to four equivalent Co(1) and four equivalent O(2) atoms to form distorted MgCo4O4 tetrahedra that share corners with four equivalent Be(1)O4 tetrahedra. All Mg(1)-Co(1) bond lengths are 2.17 Å. All Mg(1)-O(2) bond lengths are 1.88 Å. There are two inequivalent Be sites. In the first Be site, Be(1) is bonded to four equivalent O(2) atoms to form BeO4 tetrahedra that share corners with four equivalent Mg(1)Co4O4 tetrahedra. All Be(1)-O(2) bond lengths are 1.76 Å. In the second Be site, Be(2) is bonded in a tetrahedral geometry to four equivalent O(1) atoms. All Be(2)-O(1) bond lengths are 1.75 Å. Co(1) is bonded in a 7-coordinate geometry to one Mg(1), three equivalent O(1), and three equivalent O(2) atoms. All Co(1)-O(1) bond lengths are 1.98 Å. All Co(1)-O(2) bond lengths are 2.35 Å. There are two inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to one Be(2) and three equivalent Co(1) atoms. In the second O site, O(2) is bonded in a distorted linear geometry to one Mg(1), one Be(1), and three equivalent Co(1) atoms.