NbTiP3O12 crystallizes in the trigonal R3c space group. Ti(1) is bonded to three equivalent O(1) and three equivalent O(3) atoms to form TiO6 octahedra that share corners with six equivalent P(1)O4 tetrahedra. Nb(1) is bonded to three equivalent O(2) and three equivalent O(4) atoms to form NbO6 octahedra that share corners with six equivalent P(1)O4 tetrahedra. P(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form PO4 tetrahedra that share corners with two equivalent Ti(1)O6 octahedra and corners with two equivalent Nb(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 23-27°. There are four inequivalent O sites. In the first O site, O(2) is bonded in a bent 150 degrees geometry to one Nb(1) and one P(1) atom. In the second O site, O(3) is bonded in a bent 150 degrees geometry to one Ti(1) and one P(1) atom. In the third O site, O(4) is bonded in a bent 150 degrees geometry to one Nb(1) and one P(1) atom. In the fourth O site, O(1) is bonded in a bent 150 degrees geometry to one Ti(1) and one P(1) atom.
NbTiP3O12 crystallizes in the trigonal R3c space group. Ti(1) is bonded to three equivalent O(1) and three equivalent O(3) atoms to form TiO6 octahedra that share corners with six equivalent P(1)O4 tetrahedra. All Ti(1)-O(1) bond lengths are 1.98 Å. All Ti(1)-O(3) bond lengths are 1.94 Å. Nb(1) is bonded to three equivalent O(2) and three equivalent O(4) atoms to form NbO6 octahedra that share corners with six equivalent P(1)O4 tetrahedra. All Nb(1)-O(2) bond lengths are 2.01 Å. All Nb(1)-O(4) bond lengths are 1.97 Å. P(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form PO4 tetrahedra that share corners with two equivalent Ti(1)O6 octahedra and corners with two equivalent Nb(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 23-27°. The P(1)-O(1) bond length is 1.52 Å. The P(1)-O(2) bond length is 1.55 Å. The P(1)-O(3) bond length is 1.53 Å. The P(1)-O(4) bond length is 1.56 Å. There are four inequivalent O sites. In the first O site, O(2) is bonded in a bent 150 degrees geometry to one Nb(1) and one P(1) atom. In the second O site, O(3) is bonded in a bent 150 degrees geometry to one Ti(1) and one P(1) atom. In the third O site, O(4) is bonded in a bent 150 degrees geometry to one Nb(1) and one P(1) atom. In the fourth O site, O(1) is bonded in a bent 150 degrees geometry to one Ti(1) and one P(1) atom.