KMgSb(PO4)2 crystallizes in the trigonal R3 space group. K(1) is bonded in a 9-coordinate geometry to three equivalent O(1), three equivalent O(2), and three equivalent O(3) atoms. Mg(1) is bonded in a distorted rectangular see-saw-like geometry to one O(1) and three equivalent O(4) atoms. Sb(1) is bonded to three equivalent O(2) and three equivalent O(4) atoms to form distorted SbO6 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(1) and three equivalent O(2) atoms to form PO4 tetrahedra that share corners with three equivalent Sb(1)O6 octahedra. The corner-sharing octahedral tilt angles are 43°. In the second P site, P(2) is bonded to one O(3) and three equivalent O(4) atoms to form PO4 tetrahedra that share corners with three equivalent Sb(1)O6 octahedra. The corner-sharing octahedral tilt angles are 40°. There are four inequivalent O sites. In the first O site, O(1) is bonded in a distorted linear geometry to three equivalent K(1), one Mg(1), and one P(1) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one K(1), one Sb(1), and one P(1) atom. In the third O site, O(3) is bonded in a single-bond geometry to three equivalent K(1) and one P(2) atom. In the fourth O site, O(4) is bonded in a distorted bent 120 degrees geometry to one Mg(1), one Sb(1), and one P(2) atom.
KMgSb(PO4)2 crystallizes in the trigonal R3 space group. K(1) is bonded in a 9-coordinate geometry to three equivalent O(1), three equivalent O(2), and three equivalent O(3) atoms. All K(1)-O(1) bond lengths are 3.02 Å. All K(1)-O(2) bond lengths are 2.89 Å. All K(1)-O(3) bond lengths are 3.15 Å. Mg(1) is bonded in a distorted rectangular see-saw-like geometry to one O(1) and three equivalent O(4) atoms. The Mg(1)-O(1) bond length is 1.94 Å. All Mg(1)-O(4) bond lengths are 1.99 Å. Sb(1) is bonded to three equivalent O(2) and three equivalent O(4) atoms to form distorted SbO6 octahedra that share corners with three equivalent P(1)O4 tetrahedra and corners with three equivalent P(2)O4 tetrahedra. All Sb(1)-O(2) bond lengths are 2.15 Å. All Sb(1)-O(4) bond lengths are 2.59 Å. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(1) and three equivalent O(2) atoms to form PO4 tetrahedra that share corners with three equivalent Sb(1)O6 octahedra. The corner-sharing octahedral tilt angles are 43°. The P(1)-O(1) bond length is 1.53 Å. All P(1)-O(2) bond lengths are 1.56 Å. In the second P site, P(2) is bonded to one O(3) and three equivalent O(4) atoms to form PO4 tetrahedra that share corners with three equivalent Sb(1)O6 octahedra. The corner-sharing octahedral tilt angles are 40°. The P(2)-O(3) bond length is 1.53 Å. All P(2)-O(4) bond lengths are 1.57 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded in a distorted linear geometry to three equivalent K(1), one Mg(1), and one P(1) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one K(1), one Sb(1), and one P(1) atom. In the third O site, O(3) is bonded in a single-bond geometry to three equivalent K(1) and one P(2) atom. In the fourth O site, O(4) is bonded in a distorted bent 120 degrees geometry to one Mg(1), one Sb(1), and one P(2) atom.