MgBi3O7 crystallizes in the orthorhombic Pnma space group. Mg(1) is bonded in a 5-coordinate geometry to one O(3), two equivalent O(1), two equivalent O(2), and two equivalent O(4) atoms. There are two inequivalent Bi sites. In the first Bi site, Bi(1) is bonded in a 7-coordinate geometry to one O(3), two equivalent O(1), two equivalent O(2), and two equivalent O(4) atoms. In the second Bi site, Bi(2) is bonded in a distorted trigonal bipyramidal geometry to one O(3), two equivalent O(1), and two equivalent O(2) atoms. There are four inequivalent O sites. In the first O site, O(3) is bonded in a distorted bent 120 degrees geometry to one Mg(1), one Bi(2), and two equivalent Bi(1) atoms. In the second O site, O(4) is bonded in a distorted trigonal planar geometry to one Mg(1) and two equivalent Bi(1) atoms. In the third O site, O(1) is bonded to one Mg(1), one Bi(2), and two equivalent Bi(1) atoms to form a mixture of distorted edge and corner-sharing OMgBi3 tetrahedra. In the fourth O site, O(2) is bonded in a 4-coordinate geometry to one Mg(1), one Bi(2), and two equivalent Bi(1) atoms.
MgBi3O7 crystallizes in the orthorhombic Pnma space group. Mg(1) is bonded in a 5-coordinate geometry to one O(3), two equivalent O(1), two equivalent O(2), and two equivalent O(4) atoms. The Mg(1)-O(3) bond length is 2.18 Å. Both Mg(1)-O(1) bond lengths are 2.25 Å. Both Mg(1)-O(2) bond lengths are 2.75 Å. Both Mg(1)-O(4) bond lengths are 2.12 Å. There are two inequivalent Bi sites. In the first Bi site, Bi(1) is bonded in a 7-coordinate geometry to one O(3), two equivalent O(1), two equivalent O(2), and two equivalent O(4) atoms. The Bi(1)-O(3) bond length is 2.82 Å. There is one shorter (2.22 Å) and one longer (2.59 Å) Bi(1)-O(1) bond length. There is one shorter (2.35 Å) and one longer (2.42 Å) Bi(1)-O(2) bond length. There is one shorter (2.25 Å) and one longer (2.26 Å) Bi(1)-O(4) bond length. In the second Bi site, Bi(2) is bonded in a distorted trigonal bipyramidal geometry to one O(3), two equivalent O(1), and two equivalent O(2) atoms. The Bi(2)-O(3) bond length is 2.07 Å. Both Bi(2)-O(1) bond lengths are 2.16 Å. Both Bi(2)-O(2) bond lengths are 2.10 Å. There are four inequivalent O sites. In the first O site, O(3) is bonded in a distorted bent 120 degrees geometry to one Mg(1), one Bi(2), and two equivalent Bi(1) atoms. In the second O site, O(4) is bonded in a distorted trigonal planar geometry to one Mg(1) and two equivalent Bi(1) atoms. In the third O site, O(1) is bonded to one Mg(1), one Bi(2), and two equivalent Bi(1) atoms to form a mixture of distorted edge and corner-sharing OMgBi3 tetrahedra. In the fourth O site, O(2) is bonded in a 4-coordinate geometry to one Mg(1), one Bi(2), and two equivalent Bi(1) atoms.