KZr(PO4)2 crystallizes in the monoclinic P2/c space group. There are two inequivalent K sites. In the first K site, K(1) is bonded in a 8-coordinate geometry to two equivalent O(3), two equivalent O(5), two equivalent O(7), and two equivalent O(8) atoms. In the second K site, K(2) is bonded in a 8-coordinate geometry to two equivalent O(1), two equivalent O(6), two equivalent O(7), and two equivalent O(8) atoms. Zr(1) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(6) atom to form ZrO6 octahedra that share corners with three equivalent P(1)O4 tetrahedra and corners with three equivalent P(2)O4 tetrahedra. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(1), one O(2), one O(3), and one O(7) atom to form PO4 tetrahedra that share corners with three equivalent Zr(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 15-22°. In the second P site, P(2) is bonded to one O(4), one O(5), one O(6), and one O(8) atom to form PO4 tetrahedra that share corners with three equivalent Zr(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 16-26°. There are eight inequivalent O sites. In the first O site, O(5) is bonded in a distorted bent 150 degrees geometry to one K(1), one Zr(1), and one P(2) atom. In the second O site, O(6) is bonded in a 2-coordinate geometry to one K(2), one Zr(1), and one P(2) atom. In the third O site, O(7) is bonded in a distorted single-bond geometry to one K(1), one K(2), and one P(1) atom. In the fourth O site, O(8) is bonded in a distorted single-bond geometry to one K(1), one K(2), and one P(2) atom. In the fifth O site, O(1) is bonded in a distorted bent 150 degrees geometry to one K(2), one Zr(1), and one P(1) atom. In the sixth O site, O(2) is bonded in a distorted linear geometry to one Zr(1) and one P(1) atom. In the seventh O site, O(3) is bonded in a distorted linear geometry to one K(1), one Zr(1), and one P(1) atom. In the eighth O site, O(4) is bonded in a linear geometry to one Zr(1) and one P(2) atom.
KZr(PO4)2 crystallizes in the monoclinic P2/c space group. There are two inequivalent K sites. In the first K site, K(1) is bonded in a 8-coordinate geometry to two equivalent O(3), two equivalent O(5), two equivalent O(7), and two equivalent O(8) atoms. Both K(1)-O(3) bond lengths are 3.07 Å. Both K(1)-O(5) bond lengths are 2.88 Å. Both K(1)-O(7) bond lengths are 2.81 Å. Both K(1)-O(8) bond lengths are 2.99 Å. In the second K site, K(2) is bonded in a 8-coordinate geometry to two equivalent O(1), two equivalent O(6), two equivalent O(7), and two equivalent O(8) atoms. Both K(2)-O(1) bond lengths are 2.98 Å. Both K(2)-O(6) bond lengths are 3.03 Å. Both K(2)-O(7) bond lengths are 2.85 Å. Both K(2)-O(8) bond lengths are 2.78 Å. Zr(1) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(6) atom to form ZrO6 octahedra that share corners with three equivalent P(1)O4 tetrahedra and corners with three equivalent P(2)O4 tetrahedra. The Zr(1)-O(1) bond length is 2.10 Å. The Zr(1)-O(2) bond length is 2.09 Å. The Zr(1)-O(3) bond length is 2.10 Å. The Zr(1)-O(4) bond length is 2.08 Å. The Zr(1)-O(5) bond length is 2.10 Å. The Zr(1)-O(6) bond length is 2.11 Å. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(1), one O(2), one O(3), and one O(7) atom to form PO4 tetrahedra that share corners with three equivalent Zr(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 15-22°. The P(1)-O(1) bond length is 1.55 Å. The P(1)-O(2) bond length is 1.54 Å. The P(1)-O(3) bond length is 1.55 Å. The P(1)-O(7) bond length is 1.54 Å. In the second P site, P(2) is bonded to one O(4), one O(5), one O(6), and one O(8) atom to form PO4 tetrahedra that share corners with three equivalent Zr(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 16-26°. The P(2)-O(4) bond length is 1.54 Å. The P(2)-O(5) bond length is 1.55 Å. The P(2)-O(6) bond length is 1.55 Å. The P(2)-O(8) bond length is 1.54 Å. There are eight inequivalent O sites. In the first O site, O(5) is bonded in a distorted bent 150 degrees geometry to one K(1), one Zr(1), and one P(2) atom. In the second O site, O(6) is bonded in a 2-coordinate geometry to one K(2), one Zr(1), and one P(2) atom. In the third O site, O(7) is bonded in a distorted single-bond geometry to one K(1), one K(2), and one P(1) atom. In the fourth O site, O(8) is bonded in a distorted single-bond geometry to one K(1), one K(2), and one P(2) atom. In the fifth O site, O(1) is bonded in a distorted bent 150 degrees geometry to one K(2), one Zr(1), and one P(1) atom. In the sixth O site, O(2) is bonded in a distorted linear geometry to one Zr(1) and one P(1) atom. In the seventh O site, O(3) is bonded in a distorted linear geometry to one K(1), one Zr(1), and one P(1) atom. In the eighth O site, O(4) is bonded in a linear geometry to one Zr(1) and one P(2) atom.