Nb2P3O12 crystallizes in the trigonal R-3c space group. Nb(1) is bonded to three equivalent O(1) and three equivalent O(2) atoms to form NbO6 octahedra that share corners with six equivalent P(1)O4 tetrahedra. P(1) is bonded to two equivalent O(1) and two equivalent O(2) atoms to form PO4 tetrahedra that share corners with four equivalent Nb(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 23-28°. There are two 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(1) is bonded in a bent 150 degrees geometry to one Nb(1) and one P(1) atom.
Nb2P3O12 crystallizes in the trigonal R-3c space group. Nb(1) is bonded to three equivalent O(1) and three equivalent O(2) atoms to form NbO6 octahedra that share corners with six equivalent P(1)O4 tetrahedra. All Nb(1)-O(1) bond lengths are 2.00 Å. All Nb(1)-O(2) bond lengths are 2.02 Å. P(1) is bonded to two equivalent O(1) and two equivalent O(2) atoms to form PO4 tetrahedra that share corners with four equivalent Nb(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 23-28°. Both P(1)-O(1) bond lengths are 1.53 Å. Both P(1)-O(2) bond lengths are 1.52 Å. There are two 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(1) is bonded in a bent 150 degrees geometry to one Nb(1) and one P(1) atom.