NbCr2Mn3(PO4)6 crystallizes in the trigonal R3 space group. Nb(1) is bonded to three equivalent O(3) and three equivalent O(6) atoms to form NbO6 octahedra that share corners with three equivalent P(1)O4 tetrahedra, corners with three equivalent P(2)O4 tetrahedra, and  a faceface with one Cr(1)O6 octahedra. There are two inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to three equivalent O(2) and three equivalent O(6) atoms to form distorted CrO6 octahedra that share corners with three equivalent P(1)O4 tetrahedra, corners with three equivalent P(2)O4 tetrahedra,  a faceface with one Nb(1)O6 octahedra, and  a faceface with one Mn(1)O6 pentagonal pyramid. In the second Cr site, Cr(2) is bonded to three equivalent O(4) and three equivalent O(7) atoms to form CrO6 octahedra that share corners with three equivalent P(1)O4 tetrahedra, corners with three equivalent P(2)O4 tetrahedra,  a faceface with one Mn(3)O6 octahedra, and  a faceface with one Mn(2)O6 pentagonal pyramid. There are three inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to three equivalent O(2) and three equivalent O(5) atoms to form distorted MnO6 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 Cr(1)O6 octahedra. In the second Mn site, Mn(2) is bonded to three equivalent O(1) and three equivalent O(4) atoms to form distorted MnO6 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 Cr(2)O6 octahedra. In the third Mn site, Mn(3) is bonded to three equivalent O(7) and three equivalent O(8) atoms to form distorted MnO6 octahedra that share corners with three equivalent P(1)O4 tetrahedra, corners with three equivalent P(2)O4 tetrahedra, and  a faceface with one Cr(2)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 Nb(1)O6 octahedra,  a cornercorner with one Cr(1)O6 octahedra,  a cornercorner with one Cr(2)O6 octahedra,  a cornercorner with one Mn(3)O6 octahedra,  a cornercorner with one Mn(1)O6 pentagonal pyramid, and  a cornercorner with one Mn(2)O6 pentagonal pyramid. The corner-sharing octahedral tilt angles range from 23-39°. 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 Nb(1)O6 octahedra,  a cornercorner with one Cr(1)O6 octahedra,  a cornercorner with one Cr(2)O6 octahedra,  a cornercorner with one Mn(3)O6 octahedra,  a cornercorner with one Mn(1)O6 pentagonal pyramid, and  a cornercorner with one Mn(2)O6 pentagonal pyramid. The corner-sharing octahedral tilt angles range from 35-56°. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one Mn(2) and one P(2) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Cr(1), one Mn(1), and one P(1) atom. In the third O site, O(3) is bonded in a bent 150 degrees geometry to one Nb(1) and one P(1) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one Cr(2), one Mn(2), and one P(1) atom. In the fifth O site, O(5) is bonded in a bent 150 degrees geometry to one Mn(1) and one P(2) atom. In the sixth O site, O(6) is bonded in a 3-coordinate geometry to one Nb(1), one Cr(1), and one P(2) atom. In the seventh O site, O(7) is bonded in a 3-coordinate geometry to one Cr(2), one Mn(3), and one P(2) atom. In the eighth O site, O(8) is bonded in a bent 150 degrees geometry to one Mn(3) and one P(1) atom.
NbCr2Mn3(PO4)6 crystallizes in the trigonal R3 space group. Nb(1) is bonded to three equivalent O(3) and three equivalent O(6) atoms to form NbO6 octahedra that share corners with three equivalent P(1)O4 tetrahedra, corners with three equivalent P(2)O4 tetrahedra, and  a faceface with one Cr(1)O6 octahedra. All Nb(1)-O(3) bond lengths are 1.92 Å. All Nb(1)-O(6) bond lengths are 2.11 Å. There are two inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to three equivalent O(2) and three equivalent O(6) atoms to form distorted CrO6 octahedra that share corners with three equivalent P(1)O4 tetrahedra, corners with three equivalent P(2)O4 tetrahedra,  a faceface with one Nb(1)O6 octahedra, and  a faceface with one Mn(1)O6 pentagonal pyramid. All Cr(1)-O(2) bond lengths are 2.10 Å. All Cr(1)-O(6) bond lengths are 2.19 Å. In the second Cr site, Cr(2) is bonded to three equivalent O(4) and three equivalent O(7) atoms to form CrO6 octahedra that share corners with three equivalent P(1)O4 tetrahedra, corners with three equivalent P(2)O4 tetrahedra,  a faceface with one Mn(3)O6 octahedra, and  a faceface with one Mn(2)O6 pentagonal pyramid. All Cr(2)-O(4) bond lengths are 2.10 Å. All Cr(2)-O(7) bond lengths are 2.08 Å. There are three inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to three equivalent O(2) and three equivalent O(5) atoms to form distorted MnO6 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 Cr(1)O6 octahedra. All Mn(1)-O(2) bond lengths are 2.17 Å. All Mn(1)-O(5) bond lengths are 1.99 Å. In the second Mn site, Mn(2) is bonded to three equivalent O(1) and three equivalent O(4) atoms to form distorted MnO6 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 Cr(2)O6 octahedra. All Mn(2)-O(1) bond lengths are 2.05 Å. All Mn(2)-O(4) bond lengths are 2.28 Å. In the third Mn site, Mn(3) is bonded to three equivalent O(7) and three equivalent O(8) atoms to form distorted MnO6 octahedra that share corners with three equivalent P(1)O4 tetrahedra, corners with three equivalent P(2)O4 tetrahedra, and  a faceface with one Cr(2)O6 octahedra. All Mn(3)-O(7) bond lengths are 2.17 Å. All Mn(3)-O(8) bond lengths are 2.03 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 Nb(1)O6 octahedra,  a cornercorner with one Cr(1)O6 octahedra,  a cornercorner with one Cr(2)O6 octahedra,  a cornercorner with one Mn(3)O6 octahedra,  a cornercorner with one Mn(1)O6 pentagonal pyramid, and  a cornercorner with one Mn(2)O6 pentagonal pyramid. The corner-sharing octahedral tilt angles range from 23-39°. The P(1)-O(2) bond length is 1.56 Å. The P(1)-O(3) bond length is 1.60 Å. The P(1)-O(4) bond length is 1.55 Å. The P(1)-O(8) bond length is 1.50 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 Nb(1)O6 octahedra,  a cornercorner with one Cr(1)O6 octahedra,  a cornercorner with one Cr(2)O6 octahedra,  a cornercorner with one Mn(3)O6 octahedra,  a cornercorner with one Mn(1)O6 pentagonal pyramid, and  a cornercorner with one Mn(2)O6 pentagonal pyramid. The corner-sharing octahedral tilt angles range from 35-56°. The P(2)-O(1) bond length is 1.50 Å. The P(2)-O(5) bond length is 1.51 Å. The P(2)-O(6) bond length is 1.64 Å. The P(2)-O(7) bond length is 1.57 Å. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one Mn(2) and one P(2) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Cr(1), one Mn(1), and one P(1) atom. In the third O site, O(3) is bonded in a bent 150 degrees geometry to one Nb(1) and one P(1) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one Cr(2), one Mn(2), and one P(1) atom. In the fifth O site, O(5) is bonded in a bent 150 degrees geometry to one Mn(1) and one P(2) atom. In the sixth O site, O(6) is bonded in a 3-coordinate geometry to one Nb(1), one Cr(1), and one P(2) atom. In the seventh O site, O(7) is bonded in a 3-coordinate geometry to one Cr(2), one Mn(3), and one P(2) atom. In the eighth O site, O(8) is bonded in a bent 150 degrees geometry to one Mn(3) and one P(1) atom.