MgFe3Ni2Sb(PO4)6 crystallizes in the trigonal R3 space group. Mg(1) is bonded to three equivalent O(2) and three equivalent O(5) atoms to form MgO6 octahedra that share corners with three equivalent P(1)O4 tetrahedra, corners with three equivalent P(2)O4 tetrahedra, and  a faceface with one Ni(1)O6 octahedra. There are three inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in a 6-coordinate geometry to three equivalent O(1) and three equivalent O(5) atoms. In the second Fe site, Fe(2) is bonded to three equivalent O(1) and three equivalent O(4) atoms to form FeO6 octahedra that share corners with three equivalent P(1)O4 tetrahedra and corners with three equivalent P(2)O4 tetrahedra. In the third Fe site, Fe(3) is bonded to three equivalent O(7) and three equivalent O(8) atoms to form FeO6 octahedra that share corners with three equivalent P(1)O4 tetrahedra and corners with three equivalent P(2)O4 tetrahedra. There are two inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to three equivalent O(2) and three equivalent O(6) atoms to form distorted NiO6 octahedra that share corners with three equivalent P(1)O4 tetrahedra, corners with three equivalent P(2)O4 tetrahedra,  a faceface with one Mg(1)O6 octahedra, and  a faceface with one Sb(1)O6 pentagonal pyramid. In the second Ni site, Ni(2) is bonded in a 6-coordinate geometry to three equivalent O(4) and three equivalent O(7) atoms. Sb(1) is bonded to three equivalent O(3) and three equivalent O(6) atoms to form distorted SbO6 pentagonal pyramids that share corners with three equivalent P(1)O4 tetrahedra, corners with three equivalent P(2)O4 tetrahedra, and  a faceface with one Ni(1)O6 octahedra. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(2), one O(3), one O(4), and one O(8) atom to form PO4 tetrahedra that share  a cornercorner with one Mg(1)O6 octahedra,  a cornercorner with one Fe(2)O6 octahedra,  a cornercorner with one Fe(3)O6 octahedra,  a cornercorner with one Ni(1)O6 octahedra, and  a cornercorner with one Sb(1)O6 pentagonal pyramid. The corner-sharing octahedral tilt angles range from 24-51°. In the second P site, P(2) is bonded to one O(1), one O(5), one O(6), and one O(7) atom to form PO4 tetrahedra that share  a cornercorner with one Mg(1)O6 octahedra,  a cornercorner with one Fe(2)O6 octahedra,  a cornercorner with one Fe(3)O6 octahedra,  a cornercorner with one Ni(1)O6 octahedra, and  a cornercorner with one Sb(1)O6 pentagonal pyramid. The corner-sharing octahedral tilt angles range from 13-50°. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a distorted T-shaped geometry to one Fe(1), one Fe(2), and one P(2) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Mg(1), one Ni(1), and one P(1) atom. In the third O site, O(3) is bonded in a bent 150 degrees geometry to one Sb(1) and one P(1) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one Fe(2), one Ni(2), and one P(1) atom. In the fifth O site, O(5) is bonded in a distorted T-shaped geometry to one Mg(1), one Fe(1), and one P(2) atom. In the sixth O site, O(6) is bonded in a 3-coordinate geometry to one Ni(1), one Sb(1), and one P(2) atom. In the seventh O site, O(7) is bonded in a 3-coordinate geometry to one Fe(3), one Ni(2), and one P(2) atom. In the eighth O site, O(8) is bonded in a bent 150 degrees geometry to one Fe(3) and one P(1) atom.
MgFe3Ni2Sb(PO4)6 crystallizes in the trigonal R3 space group. Mg(1) is bonded to three equivalent O(2) and three equivalent O(5) atoms to form MgO6 octahedra that share corners with three equivalent P(1)O4 tetrahedra, corners with three equivalent P(2)O4 tetrahedra, and  a faceface with one Ni(1)O6 octahedra. All Mg(1)-O(2) bond lengths are 2.03 Å. All Mg(1)-O(5) bond lengths are 2.17 Å. There are three inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in a 6-coordinate geometry to three equivalent O(1) and three equivalent O(5) atoms. All Fe(1)-O(1) bond lengths are 2.10 Å. All Fe(1)-O(5) bond lengths are 2.09 Å. In the second Fe site, Fe(2) is bonded to three equivalent O(1) and three equivalent O(4) atoms to form FeO6 octahedra that share corners with three equivalent P(1)O4 tetrahedra and corners with three equivalent P(2)O4 tetrahedra. All Fe(2)-O(1) bond lengths are 2.12 Å. All Fe(2)-O(4) bond lengths are 1.97 Å. In the third Fe site, Fe(3) is bonded to three equivalent O(7) and three equivalent O(8) atoms to form FeO6 octahedra that share corners with three equivalent P(1)O4 tetrahedra and corners with three equivalent P(2)O4 tetrahedra. All Fe(3)-O(7) bond lengths are 2.11 Å. All Fe(3)-O(8) bond lengths are 1.94 Å. There are two inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to three equivalent O(2) and three equivalent O(6) atoms to form distorted NiO6 octahedra that share corners with three equivalent P(1)O4 tetrahedra, corners with three equivalent P(2)O4 tetrahedra,  a faceface with one Mg(1)O6 octahedra, and  a faceface with one Sb(1)O6 pentagonal pyramid. All Ni(1)-O(2) bond lengths are 2.12 Å. All Ni(1)-O(6) bond lengths are 2.20 Å. In the second Ni site, Ni(2) is bonded in a 6-coordinate geometry to three equivalent O(4) and three equivalent O(7) atoms. All Ni(2)-O(4) bond lengths are 2.25 Å. All Ni(2)-O(7) bond lengths are 2.15 Å. Sb(1) is bonded to three equivalent O(3) and three equivalent O(6) atoms to form distorted SbO6 pentagonal pyramids that share corners with three equivalent P(1)O4 tetrahedra, corners with three equivalent P(2)O4 tetrahedra, and  a faceface with one Ni(1)O6 octahedra. All Sb(1)-O(3) bond lengths are 2.08 Å. All Sb(1)-O(6) bond lengths are 2.19 Å. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(2), one O(3), one O(4), and one O(8) atom to form PO4 tetrahedra that share  a cornercorner with one Mg(1)O6 octahedra,  a cornercorner with one Fe(2)O6 octahedra,  a cornercorner with one Fe(3)O6 octahedra,  a cornercorner with one Ni(1)O6 octahedra, and  a cornercorner with one Sb(1)O6 pentagonal pyramid. The corner-sharing octahedral tilt angles range from 24-51°. The P(1)-O(2) bond length is 1.54 Å. The P(1)-O(3) bond length is 1.56 Å. The P(1)-O(4) bond length is 1.57 Å. The P(1)-O(8) bond length is 1.52 Å. In the second P site, P(2) is bonded to one O(1), one O(5), one O(6), and one O(7) atom to form PO4 tetrahedra that share  a cornercorner with one Mg(1)O6 octahedra,  a cornercorner with one Fe(2)O6 octahedra,  a cornercorner with one Fe(3)O6 octahedra,  a cornercorner with one Ni(1)O6 octahedra, and  a cornercorner with one Sb(1)O6 pentagonal pyramid. The corner-sharing octahedral tilt angles range from 13-50°. The P(2)-O(1) bond length is 1.56 Å. The P(2)-O(5) bond length is 1.54 Å. The P(2)-O(6) bond length is 1.58 Å. The P(2)-O(7) bond length is 1.54 Å. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a distorted T-shaped geometry to one Fe(1), one Fe(2), and one P(2) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Mg(1), one Ni(1), and one P(1) atom. In the third O site, O(3) is bonded in a bent 150 degrees geometry to one Sb(1) and one P(1) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one Fe(2), one Ni(2), and one P(1) atom. In the fifth O site, O(5) is bonded in a distorted T-shaped geometry to one Mg(1), one Fe(1), and one P(2) atom. In the sixth O site, O(6) is bonded in a 3-coordinate geometry to one Ni(1), one Sb(1), and one P(2) atom. In the seventh O site, O(7) is bonded in a 3-coordinate geometry to one Fe(3), one Ni(2), and one P(2) atom. In the eighth O site, O(8) is bonded in a bent 150 degrees geometry to one Fe(3) and one P(1) atom.