K4MgV2O7 crystallizes in the monoclinic C2/m space group. There are three inequivalent K sites. In the first K site, K(1) is bonded in a 4-coordinate geometry to one O(1), one O(3), and two equivalent O(2) atoms. In the second K site, K(2) is bonded in a distorted square co-planar geometry to four equivalent O(2) atoms. In the third K site, K(3) is bonded in a distorted linear geometry to two equivalent O(1) atoms. Mg(1) is bonded in a square co-planar geometry to four equivalent O(2) atoms. V(1) is bonded to one O(1), one O(3), and two equivalent O(2) atoms to form corner-sharing VO4 tetrahedra. There are three inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one K(1), one K(3), and one V(1) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to one K(1), one K(2), one Mg(1), and one V(1) atom. In the third O site, O(3) is bonded in a distorted linear geometry to two equivalent K(1) and two equivalent V(1) atoms.
K4MgV2O7 crystallizes in the monoclinic C2/m space group. There are three inequivalent K sites. In the first K site, K(1) is bonded in a 4-coordinate geometry to one O(1), one O(3), and two equivalent O(2) atoms. The K(1)-O(1) bond length is 2.70 Å. The K(1)-O(3) bond length is 3.05 Å. Both K(1)-O(2) bond lengths are 2.94 Å. In the second K site, K(2) is bonded in a distorted square co-planar geometry to four equivalent O(2) atoms. All K(2)-O(2) bond lengths are 2.51 Å. In the third K site, K(3) is bonded in a distorted linear geometry to two equivalent O(1) atoms. Both K(3)-O(1) bond lengths are 2.61 Å. Mg(1) is bonded in a square co-planar geometry to four equivalent O(2) atoms. All Mg(1)-O(2) bond lengths are 2.05 Å. V(1) is bonded to one O(1), one O(3), and two equivalent O(2) atoms to form corner-sharing VO4 tetrahedra. The V(1)-O(1) bond length is 1.74 Å. The V(1)-O(3) bond length is 1.89 Å. Both V(1)-O(2) bond lengths are 1.85 Å. There are three inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one K(1), one K(3), and one V(1) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to one K(1), one K(2), one Mg(1), and one V(1) atom. In the third O site, O(3) is bonded in a distorted linear geometry to two equivalent K(1) and two equivalent V(1) atoms.