TiNi3Sb2(PO4)6 crystallizes in the trigonal R3 space group. Ti(1) is bonded to three equivalent O(3) and three equivalent O(6) atoms to form TiO6 octahedra that share corners with three equivalent P(1)O4 tetrahedra and corners with three equivalent P(2)O4 tetrahedra. There are three inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to three equivalent O(2) and three equivalent O(5) atoms to form distorted NiO6 octahedra that share corners with three equivalent P(1)O4 tetrahedra and corners with three equivalent P(2)O4 tetrahedra. In the second Ni site, Ni(2) is bonded in a 6-coordinate geometry to three equivalent O(1) and three equivalent O(4) atoms. In the third Ni site, Ni(3) is bonded to three equivalent O(7) and three equivalent O(8) atoms to form distorted NiO6 octahedra that share corners with three equivalent P(1)O4 tetrahedra, corners with three equivalent P(2)O4 tetrahedra, and  a faceface with one Sb(2)O6 octahedra. There are two inequivalent Sb sites. In the first Sb site, Sb(1) is bonded in a 6-coordinate geometry to three equivalent O(2) and three equivalent O(6) atoms. In the second Sb site, Sb(2) is bonded to three equivalent O(4) and three equivalent O(7) atoms to form distorted SbO6 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(3)O6 octahedra. There are two inequivalent P sites. In the first P site, P(1) 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 Ti(1)O6 octahedra,  a cornercorner with one Ni(1)O6 octahedra,  a cornercorner with one Ni(3)O6 octahedra, and  a cornercorner with one Sb(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 36-53°. In the second P site, P(2) 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 Ti(1)O6 octahedra,  a cornercorner with one Ni(1)O6 octahedra,  a cornercorner with one Ni(3)O6 octahedra, and  a cornercorner with one Sb(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 23-47°. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one Ni(2) and one P(1) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Ni(1), one Sb(1), and one P(2) atom. In the third O site, O(3) is bonded in a bent 150 degrees geometry to one Ti(1) and one P(2) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one Ni(2), one Sb(2), and one P(2) atom. In the fifth O site, O(5) is bonded in a bent 150 degrees geometry to one Ni(1) and one P(1) atom. In the sixth O site, O(6) is bonded in a 3-coordinate geometry to one Ti(1), one Sb(1), and one P(1) atom. In the seventh O site, O(7) is bonded in a 3-coordinate geometry to one Ni(3), one Sb(2), and one P(1) atom. In the eighth O site, O(8) is bonded in a bent 150 degrees geometry to one Ni(3) and one P(2) atom.
TiNi3Sb2(PO4)6 crystallizes in the trigonal R3 space group. Ti(1) is bonded to three equivalent O(3) and three equivalent O(6) atoms to form TiO6 octahedra that share corners with three equivalent P(1)O4 tetrahedra and corners with three equivalent P(2)O4 tetrahedra. All Ti(1)-O(3) bond lengths are 1.91 Å. All Ti(1)-O(6) bond lengths are 1.99 Å. There are three inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to three equivalent O(2) and three equivalent O(5) atoms to form distorted NiO6 octahedra that share corners with three equivalent P(1)O4 tetrahedra and corners with three equivalent P(2)O4 tetrahedra. All Ni(1)-O(2) bond lengths are 2.16 Å. All Ni(1)-O(5) bond lengths are 1.92 Å. In the second Ni site, Ni(2) is bonded in a 6-coordinate geometry to three equivalent O(1) and three equivalent O(4) atoms. All Ni(2)-O(1) bond lengths are 2.00 Å. All Ni(2)-O(4) bond lengths are 2.31 Å. In the third Ni site, Ni(3) is bonded to three equivalent O(7) and three equivalent O(8) atoms to form distorted NiO6 octahedra that share corners with three equivalent P(1)O4 tetrahedra, corners with three equivalent P(2)O4 tetrahedra, and  a faceface with one Sb(2)O6 octahedra. All Ni(3)-O(7) bond lengths are 2.17 Å. All Ni(3)-O(8) bond lengths are 2.01 Å. There are two inequivalent Sb sites. In the first Sb site, Sb(1) is bonded in a 6-coordinate geometry to three equivalent O(2) and three equivalent O(6) atoms. All Sb(1)-O(2) bond lengths are 2.14 Å. All Sb(1)-O(6) bond lengths are 2.55 Å. In the second Sb site, Sb(2) is bonded to three equivalent O(4) and three equivalent O(7) atoms to form distorted SbO6 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(3)O6 octahedra. All Sb(2)-O(4) bond lengths are 2.12 Å. All Sb(2)-O(7) bond lengths are 2.10 Å. There are two inequivalent P sites. In the first P site, P(1) 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 Ti(1)O6 octahedra,  a cornercorner with one Ni(1)O6 octahedra,  a cornercorner with one Ni(3)O6 octahedra, and  a cornercorner with one Sb(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 36-53°. The P(1)-O(1) bond length is 1.51 Å. The P(1)-O(5) bond length is 1.50 Å. The P(1)-O(6) bond length is 1.57 Å. The P(1)-O(7) bond length is 1.63 Å. In the second P site, P(2) 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 Ti(1)O6 octahedra,  a cornercorner with one Ni(1)O6 octahedra,  a cornercorner with one Ni(3)O6 octahedra, and  a cornercorner with one Sb(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 23-47°. The P(2)-O(2) bond length is 1.57 Å. The P(2)-O(3) bond length is 1.53 Å. The P(2)-O(4) bond length is 1.61 Å. The P(2)-O(8) bond length is 1.50 Å. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one Ni(2) and one P(1) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Ni(1), one Sb(1), and one P(2) atom. In the third O site, O(3) is bonded in a bent 150 degrees geometry to one Ti(1) and one P(2) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one Ni(2), one Sb(2), and one P(2) atom. In the fifth O site, O(5) is bonded in a bent 150 degrees geometry to one Ni(1) and one P(1) atom. In the sixth O site, O(6) is bonded in a 3-coordinate geometry to one Ti(1), one Sb(1), and one P(1) atom. In the seventh O site, O(7) is bonded in a 3-coordinate geometry to one Ni(3), one Sb(2), and one P(1) atom. In the eighth O site, O(8) is bonded in a bent 150 degrees geometry to one Ni(3) and one P(2) atom.