KNbCPO7 crystallizes in the monoclinic P2_1 space group. K(1) is bonded in a 7-coordinate geometry to one O(1), one O(2), one O(3), one O(6), one O(7), and two equivalent O(5) atoms. Nb(1) is bonded to one O(2), one O(3), one O(4), one O(5), one O(6), and one O(7) atom to form NbO6 octahedra that share corners with four equivalent P(1)O4 tetrahedra. C(1) is bonded in a trigonal planar geometry to one O(1), one O(2), and one O(3) atom. P(1) is bonded to one O(4), one O(5), one O(6), and one O(7) atom to form PO4 tetrahedra that share corners with four equivalent Nb(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 22-37°. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a distorted bent 150 degrees geometry to one K(1) and one C(1) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one K(1), one Nb(1), and one C(1) atom. In the third O site, O(3) is bonded in a distorted trigonal non-coplanar geometry to one K(1), one Nb(1), and one C(1) atom. In the fourth O site, O(4) is bonded in a bent 150 degrees geometry to one Nb(1) and one P(1) atom. In the fifth O site, O(5) is bonded in a distorted bent 150 degrees geometry to two equivalent K(1), one Nb(1), and one P(1) atom. In the sixth O site, O(6) is bonded in a 2-coordinate geometry to one K(1), one Nb(1), and one P(1) atom. In the seventh O site, O(7) is bonded in a 3-coordinate geometry to one K(1), one Nb(1), and one P(1) atom.
KNbCPO7 crystallizes in the monoclinic P2_1 space group. K(1) is bonded in a 7-coordinate geometry to one O(1), one O(2), one O(3), one O(6), one O(7), and two equivalent O(5) atoms. The K(1)-O(1) bond length is 2.54 Å. The K(1)-O(2) bond length is 2.80 Å. The K(1)-O(3) bond length is 2.66 Å. The K(1)-O(6) bond length is 3.06 Å. The K(1)-O(7) bond length is 3.06 Å. There is one shorter (2.96 Å) and one longer (3.16 Å) K(1)-O(5) bond length. Nb(1) is bonded to one O(2), one O(3), one O(4), one O(5), one O(6), and one O(7) atom to form NbO6 octahedra that share corners with four equivalent P(1)O4 tetrahedra. The Nb(1)-O(2) bond length is 2.07 Å. The Nb(1)-O(3) bond length is 2.07 Å. The Nb(1)-O(4) bond length is 1.97 Å. The Nb(1)-O(5) bond length is 2.09 Å. The Nb(1)-O(6) bond length is 2.15 Å. The Nb(1)-O(7) bond length is 2.18 Å. C(1) is bonded in a trigonal planar geometry to one O(1), one O(2), and one O(3) atom. The C(1)-O(1) bond length is 1.22 Å. The C(1)-O(2) bond length is 1.36 Å. The C(1)-O(3) bond length is 1.35 Å. P(1) is bonded to one O(4), one O(5), one O(6), and one O(7) atom to form PO4 tetrahedra that share corners with four equivalent Nb(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 22-37°. The P(1)-O(4) bond length is 1.58 Å. The P(1)-O(5) bond length is 1.55 Å. The P(1)-O(6) bond length is 1.53 Å. The P(1)-O(7) bond length is 1.54 Å. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a distorted bent 150 degrees geometry to one K(1) and one C(1) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one K(1), one Nb(1), and one C(1) atom. In the third O site, O(3) is bonded in a distorted trigonal non-coplanar geometry to one K(1), one Nb(1), and one C(1) atom. In the fourth O site, O(4) is bonded in a bent 150 degrees geometry to one Nb(1) and one P(1) atom. In the fifth O site, O(5) is bonded in a distorted bent 150 degrees geometry to two equivalent K(1), one Nb(1), and one P(1) atom. In the sixth O site, O(6) is bonded in a 2-coordinate geometry to one K(1), one Nb(1), and one P(1) atom. In the seventh O site, O(7) is bonded in a 3-coordinate geometry to one K(1), one Nb(1), and one P(1) atom.