KNaHf4(PO4)6 crystallizes in the trigonal R-3 space group. K(1) is bonded in a distorted hexagonal planar geometry to six equivalent O(3) atoms. Na(1) is bonded in a distorted hexagonal planar geometry to six equivalent O(4) atoms. There are two inequivalent Hf sites. In the first Hf site, Hf(1) is bonded to three equivalent O(1) and three equivalent O(4) atoms to form HfO6 octahedra that share corners with six equivalent P(1)O4 tetrahedra. In the second Hf site, Hf(2) is bonded to three equivalent O(2) and three equivalent O(3) atoms to form HfO6 octahedra that share corners with six equivalent P(1)O4 tetrahedra. P(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form PO4 tetrahedra that share corners with two equivalent Hf(1)O6 octahedra and corners with two equivalent Hf(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 23-35°. There are four inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one Hf(1) and one P(1) atom. In the second O site, O(2) is bonded in a bent 150 degrees geometry to one Hf(2) and one P(1) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one K(1), one Hf(2), and one P(1) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one Na(1), one Hf(1), and one P(1) atom.
KNaHf4(PO4)6 crystallizes in the trigonal R-3 space group. K(1) is bonded in a distorted hexagonal planar geometry to six equivalent O(3) atoms. All K(1)-O(3) bond lengths are 2.67 Å. Na(1) is bonded in a distorted hexagonal planar geometry to six equivalent O(4) atoms. All Na(1)-O(4) bond lengths are 2.60 Å. There are two inequivalent Hf sites. In the first Hf site, Hf(1) is bonded to three equivalent O(1) and three equivalent O(4) atoms to form HfO6 octahedra that share corners with six equivalent P(1)O4 tetrahedra. All Hf(1)-O(1) bond lengths are 2.06 Å. All Hf(1)-O(4) bond lengths are 2.09 Å. In the second Hf site, Hf(2) is bonded to three equivalent O(2) and three equivalent O(3) atoms to form HfO6 octahedra that share corners with six equivalent P(1)O4 tetrahedra. All Hf(2)-O(2) bond lengths are 2.04 Å. All Hf(2)-O(3) bond lengths are 2.08 Å. P(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form PO4 tetrahedra that share corners with two equivalent Hf(1)O6 octahedra and corners with two equivalent Hf(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 23-35°. 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 1.54 Å. The P(1)-O(4) bond length is 1.55 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one Hf(1) and one P(1) atom. In the second O site, O(2) is bonded in a bent 150 degrees geometry to one Hf(2) and one P(1) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one K(1), one Hf(2), and one P(1) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one Na(1), one Hf(1), and one P(1) atom.