CsMgNb(PO4)2 crystallizes in the monoclinic Cm space group. Cs(1) is bonded in a 10-coordinate geometry to two equivalent O(1), two equivalent O(6), three equivalent O(3), and three equivalent O(4) atoms. Mg(1) is bonded in a 3-coordinate geometry to one O(5) and two equivalent O(1) atoms. Nb(1) is bonded to one O(2), one O(5), two equivalent O(1), and two equivalent O(6) atoms to form NbO6 octahedra that share corners with three equivalent P(1)O4 tetrahedra and corners with three equivalent P(2)O4 tetrahedra. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(4), one O(5), and two equivalent O(6) atoms to form PO4 tetrahedra that share corners with three equivalent Nb(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 32-39°. In the second P site, P(2) is bonded to one O(2), one O(3), and two equivalent O(1) atoms to form PO4 tetrahedra that share corners with three equivalent Nb(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 19-44°. There are six inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Cs(1), one Mg(1), one Nb(1), and one P(2) atom. In the second O site, O(2) is bonded in a 2-coordinate geometry to one Nb(1) and one P(2) atom. In the third O site, O(3) is bonded in a distorted single-bond geometry to three equivalent Cs(1) and one P(2) atom. In the fourth O site, O(4) is bonded in a distorted single-bond geometry to three equivalent Cs(1) and one P(1) atom. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to one Mg(1), one Nb(1), and one P(1) atom. In the sixth O site, O(6) is bonded in a distorted bent 150 degrees geometry to one Cs(1), one Nb(1), and one P(1) atom.
CsMgNb(PO4)2 crystallizes in the monoclinic Cm space group. Cs(1) is bonded in a 10-coordinate geometry to two equivalent O(1), two equivalent O(6), three equivalent O(3), and three equivalent O(4) atoms. Both Cs(1)-O(1) bond lengths are 3.72 Å. Both Cs(1)-O(6) bond lengths are 3.24 Å. There is one shorter (3.14 Å) and two longer (3.59 Å) Cs(1)-O(3) bond lengths. There is one shorter (3.08 Å) and two longer (3.33 Å) Cs(1)-O(4) bond lengths. Mg(1) is bonded in a 3-coordinate geometry to one O(5) and two equivalent O(1) atoms. The Mg(1)-O(5) bond length is 1.95 Å. Both Mg(1)-O(1) bond lengths are 2.06 Å. Nb(1) is bonded to one O(2), one O(5), two equivalent O(1), and two equivalent O(6) atoms to form NbO6 octahedra that share corners with three equivalent P(1)O4 tetrahedra and corners with three equivalent P(2)O4 tetrahedra. The Nb(1)-O(2) bond length is 2.21 Å. The Nb(1)-O(5) bond length is 2.22 Å. Both Nb(1)-O(1) bond lengths are 2.20 Å. Both Nb(1)-O(6) bond lengths are 2.05 Å. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(4), one O(5), and two equivalent O(6) atoms to form PO4 tetrahedra that share corners with three equivalent Nb(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 32-39°. The P(1)-O(4) bond length is 1.50 Å. The P(1)-O(5) bond length is 1.59 Å. Both P(1)-O(6) bond lengths are 1.57 Å. In the second P site, P(2) is bonded to one O(2), one O(3), and two equivalent O(1) atoms to form PO4 tetrahedra that share corners with three equivalent Nb(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 19-44°. The P(2)-O(2) bond length is 1.54 Å. The P(2)-O(3) bond length is 1.50 Å. Both P(2)-O(1) bond lengths are 1.61 Å. There are six inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Cs(1), one Mg(1), one Nb(1), and one P(2) atom. In the second O site, O(2) is bonded in a 2-coordinate geometry to one Nb(1) and one P(2) atom. In the third O site, O(3) is bonded in a distorted single-bond geometry to three equivalent Cs(1) and one P(2) atom. In the fourth O site, O(4) is bonded in a distorted single-bond geometry to three equivalent Cs(1) and one P(1) atom. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to one Mg(1), one Nb(1), and one P(1) atom. In the sixth O site, O(6) is bonded in a distorted bent 150 degrees geometry to one Cs(1), one Nb(1), and one P(1) atom.