MgB2O7 crystallizes in the tetragonal P4_2/n space group. Mg(1) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms to form MgO6 octahedra that share corners with six equivalent B(1)O4 tetrahedra. B(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form BO4 tetrahedra that share corners with three equivalent Mg(1)O6 octahedra and  a cornercorner with one B(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 31-53°. There are four inequivalent O sites. In the first O site, O(4) is bonded in a bent 120 degrees geometry to one Mg(1) and one B(1) atom. In the second O site, O(1) is bonded in a bent 120 degrees geometry to two equivalent B(1) atoms. In the third O site, O(2) is bonded in a bent 150 degrees geometry to one Mg(1) and one B(1) atom. In the fourth O site, O(3) is bonded in a bent 120 degrees geometry to one Mg(1) and one B(1) atom.
MgB2O7 crystallizes in the tetragonal P4_2/n space group. Mg(1) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms to form MgO6 octahedra that share corners with six equivalent B(1)O4 tetrahedra. Both Mg(1)-O(2) bond lengths are 2.05 Å. Both Mg(1)-O(3) bond lengths are 2.09 Å. Both Mg(1)-O(4) bond lengths are 2.09 Å. B(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form BO4 tetrahedra that share corners with three equivalent Mg(1)O6 octahedra and  a cornercorner with one B(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 31-53°. The B(1)-O(1) bond length is 1.50 Å. The B(1)-O(2) bond length is 1.42 Å. The B(1)-O(3) bond length is 1.44 Å. The B(1)-O(4) bond length is 1.44 Å. There are four inequivalent O sites. In the first O site, O(4) is bonded in a bent 120 degrees geometry to one Mg(1) and one B(1) atom. In the second O site, O(1) is bonded in a bent 120 degrees geometry to two equivalent B(1) atoms. In the third O site, O(2) is bonded in a bent 150 degrees geometry to one Mg(1) and one B(1) atom. In the fourth O site, O(3) is bonded in a bent 120 degrees geometry to one Mg(1) and one B(1) atom.