KFeCPO7 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. Fe(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 FeO6 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 Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 31-41°. 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 Fe(1), and one C(1) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one K(1), one Fe(1), and one C(1) atom. In the fourth O site, O(4) is bonded in a bent 150 degrees geometry to one Fe(1) and one P(1) atom. In the fifth O site, O(5) is bonded in a 2-coordinate geometry to two equivalent K(1), one Fe(1), and one P(1) atom. In the sixth O site, O(6) is bonded in a distorted bent 150 degrees geometry to one K(1), one Fe(1), and one P(1) atom. In the seventh O site, O(7) is bonded in a distorted bent 150 degrees geometry to one K(1), one Fe(1), and one P(1) atom.
KFeCPO7 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 2.66 Å. The K(1)-O(2) bond length is 2.85 Å. The K(1)-O(3) bond length is 2.74 Å. The K(1)-O(6) bond length is 3.03 Å. The K(1)-O(7) bond length is 2.91 Å. There is one shorter (2.78 Å) and one longer (3.11 Å) K(1)-O(5) bond length. Fe(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 FeO6 octahedra that share corners with four equivalent P(1)O4 tetrahedra. The Fe(1)-O(2) bond length is 2.19 Å. The Fe(1)-O(3) bond length is 2.13 Å. The Fe(1)-O(4) bond length is 1.96 Å. The Fe(1)-O(5) bond length is 2.03 Å. The Fe(1)-O(6) bond length is 1.95 Å. The Fe(1)-O(7) bond length is 1.95 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 1.26 Å. The C(1)-O(2) bond length is 1.30 Å. The C(1)-O(3) bond length is 1.30 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 Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 31-41°. The P(1)-O(4) bond length is 1.54 Å. The P(1)-O(5) bond length is 1.55 Å. The P(1)-O(6) bond length is 1.55 Å. The P(1)-O(7) bond length is 1.56 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 Fe(1), and one C(1) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one K(1), one Fe(1), and one C(1) atom. In the fourth O site, O(4) is bonded in a bent 150 degrees geometry to one Fe(1) and one P(1) atom. In the fifth O site, O(5) is bonded in a 2-coordinate geometry to two equivalent K(1), one Fe(1), and one P(1) atom. In the sixth O site, O(6) is bonded in a distorted bent 150 degrees geometry to one K(1), one Fe(1), and one P(1) atom. In the seventh O site, O(7) is bonded in a distorted bent 150 degrees geometry to one K(1), one Fe(1), and one P(1) atom.