K3MgYV2O8 crystallizes in the monoclinic C2 space group. There are two inequivalent K sites. In the first K site, K(1) is bonded in a 3-coordinate geometry to one O(1), one O(2), one O(3), and two equivalent O(4) atoms. In the second K site, K(2) is bonded in a linear geometry to two equivalent O(4) atoms. Mg(1) is bonded in a square co-planar geometry to two equivalent O(2) and two equivalent O(3) atoms. Y(1) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms to form YO6 octahedra that share corners with six equivalent V(1)O4 tetrahedra. V(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form VO4 tetrahedra that share corners with three equivalent Y(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 5-35°. There are four inequivalent O sites. In the first O site, O(1) is bonded in a distorted linear geometry to one K(1) and one V(1) atom. In the second O site, O(2) is bonded in a distorted rectangular see-saw-like geometry to one K(1), one Mg(1), one Y(1), and one V(1) atom. In the third O site, O(3) is bonded in a distorted rectangular see-saw-like geometry to one K(1), one Mg(1), one Y(1), and one V(1) atom. In the fourth O site, O(4) is bonded in a 5-coordinate geometry to one K(2), two equivalent K(1), one Y(1), and one V(1) atom.
K3MgYV2O8 crystallizes in the monoclinic C2 space group. There are two inequivalent K sites. In the first K site, K(1) is bonded in a 3-coordinate geometry to one O(1), one O(2), one O(3), and two equivalent O(4) atoms. The K(1)-O(1) bond length is 2.52 Å. The K(1)-O(2) bond length is 2.88 Å. The K(1)-O(3) bond length is 2.88 Å. Both K(1)-O(4) bond lengths are 3.21 Å. In the second K site, K(2) is bonded in a linear geometry to two equivalent O(4) atoms. Both K(2)-O(4) bond lengths are 2.78 Å. Mg(1) is bonded in a square co-planar geometry to two equivalent O(2) and two equivalent O(3) atoms. Both Mg(1)-O(2) bond lengths are 1.99 Å. Both Mg(1)-O(3) bond lengths are 1.99 Å. Y(1) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms to form YO6 octahedra that share corners with six equivalent V(1)O4 tetrahedra. Both Y(1)-O(2) bond lengths are 2.27 Å. Both Y(1)-O(3) bond lengths are 2.27 Å. Both Y(1)-O(4) bond lengths are 2.34 Å. V(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form VO4 tetrahedra that share corners with three equivalent Y(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 5-35°. The V(1)-O(1) bond length is 1.72 Å. The V(1)-O(2) bond length is 1.92 Å. The V(1)-O(3) bond length is 1.92 Å. The V(1)-O(4) bond length is 1.79 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded in a distorted linear geometry to one K(1) and one V(1) atom. In the second O site, O(2) is bonded in a distorted rectangular see-saw-like geometry to one K(1), one Mg(1), one Y(1), and one V(1) atom. In the third O site, O(3) is bonded in a distorted rectangular see-saw-like geometry to one K(1), one Mg(1), one Y(1), and one V(1) atom. In the fourth O site, O(4) is bonded in a 5-coordinate geometry to one K(2), two equivalent K(1), one Y(1), and one V(1) atom.