K4P6O19NiO6 crystallizes in the orthorhombic Fmm2 space group. The structure consists of four NiO6 clusters inside a K4P6O19 framework. In each NiO6 cluster, Ni(1) is bonded in an octahedral geometry to two equivalent O(7), two equivalent O(8), and two equivalent O(9) atoms. There are three inequivalent O sites. In the first O site, O(9) is bonded in a single-bond geometry to one Ni(1) atom. In the second O site, O(8) is bonded in a single-bond geometry to one Ni(1) atom. In the third O site, O(7) is bonded in a single-bond geometry to one Ni(1) atom. In the K4P6O19 framework, there are two inequivalent K sites. In the first K site, K(1) is bonded to two equivalent O(3), two equivalent O(4), and two equivalent O(6) atoms to form distorted KO6 octahedra that share corners with two equivalent P(2)O4 tetrahedra, corners with four equivalent P(1)O4 tetrahedra, edges with two equivalent K(1)O6 octahedra, and edges with two equivalent K(2)O6 octahedra. In the second K site, K(2) is bonded to one O(10), one O(3), two equivalent O(5), and two equivalent O(6) atoms to form distorted KO6 octahedra that share  a cornercorner with one K(2)O6 octahedra,  a cornercorner with one P(1)O4 tetrahedra, corners with four equivalent P(2)O4 tetrahedra, and edges with two equivalent K(1)O6 octahedra. The corner-sharing octahedral tilt angles are 61°. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(3), one O(4), and two equivalent O(1) atoms to form PO4 tetrahedra that share  a cornercorner with one K(2)O6 octahedra, corners with four equivalent K(1)O6 octahedra, and corners with two equivalent P(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 37-59°. In the second P site, P(2) is bonded to one O(1), one O(2), one O(5), and one O(6) atom to form PO4 tetrahedra that share  a cornercorner with one K(1)O6 octahedra, corners with two equivalent K(2)O6 octahedra,  a cornercorner with one P(1)O4 tetrahedra, and  a cornercorner with one P(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 54-66°. There are seven inequivalent O sites. In the first O site, O(10) is bonded in a bent 120 degrees geometry to two equivalent K(2) atoms. In the second O site, O(1) is bonded in a bent 120 degrees geometry to one P(1) and one P(2) atom. In the third O site, O(2) is bonded in a distorted bent 150 degrees geometry to two equivalent P(2) atoms. In the fourth O site, O(3) is bonded in a distorted single-bond geometry to one K(2), two equivalent K(1), and one P(1) atom. In the fifth O site, O(4) is bonded in a distorted single-bond geometry to two equivalent K(1) and one P(1) atom. In the sixth O site, O(5) is bonded in a distorted bent 120 degrees geometry to one K(2) and one P(2) atom. In the seventh O site, O(6) is bonded in a distorted single-bond geometry to one K(1), one K(2), and one P(2) atom.
K4P6O19NiO6 crystallizes in the orthorhombic Fmm2 space group. The structure consists of four NiO6 clusters inside a K4P6O19 framework. In each NiO6 cluster, Ni(1) is bonded in an octahedral geometry to two equivalent O(7), two equivalent O(8), and two equivalent O(9) atoms. Both Ni(1)-O(7) bond lengths are 1.84 Å. Both Ni(1)-O(8) bond lengths are 1.84 Å. Both Ni(1)-O(9) bond lengths are 1.82 Å. There are three inequivalent O sites. In the first O site, O(9) is bonded in a single-bond geometry to one Ni(1) atom. In the second O site, O(8) is bonded in a single-bond geometry to one Ni(1) atom. In the third O site, O(7) is bonded in a single-bond geometry to one Ni(1) atom. In the K4P6O19 framework, there are two inequivalent K sites. In the first K site, K(1) is bonded to two equivalent O(3), two equivalent O(4), and two equivalent O(6) atoms to form distorted KO6 octahedra that share corners with two equivalent P(2)O4 tetrahedra, corners with four equivalent P(1)O4 tetrahedra, edges with two equivalent K(1)O6 octahedra, and edges with two equivalent K(2)O6 octahedra. Both K(1)-O(3) bond lengths are 2.72 Å. Both K(1)-O(4) bond lengths are 2.66 Å. Both K(1)-O(6) bond lengths are 2.83 Å. In the second K site, K(2) is bonded to one O(10), one O(3), two equivalent O(5), and two equivalent O(6) atoms to form distorted KO6 octahedra that share  a cornercorner with one K(2)O6 octahedra,  a cornercorner with one P(1)O4 tetrahedra, corners with four equivalent P(2)O4 tetrahedra, and edges with two equivalent K(1)O6 octahedra. The corner-sharing octahedral tilt angles are 61°. The K(2)-O(10) bond length is 2.74 Å. The K(2)-O(3) bond length is 3.12 Å. Both K(2)-O(5) bond lengths are 2.66 Å. Both K(2)-O(6) bond lengths are 2.88 Å. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(3), one O(4), and two equivalent O(1) atoms to form PO4 tetrahedra that share  a cornercorner with one K(2)O6 octahedra, corners with four equivalent K(1)O6 octahedra, and corners with two equivalent P(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 37-59°. The P(1)-O(3) bond length is 1.49 Å. The P(1)-O(4) bond length is 1.49 Å. Both P(1)-O(1) bond lengths are 1.65 Å. In the second P site, P(2) is bonded to one O(1), one O(2), one O(5), and one O(6) atom to form PO4 tetrahedra that share  a cornercorner with one K(1)O6 octahedra, corners with two equivalent K(2)O6 octahedra,  a cornercorner with one P(1)O4 tetrahedra, and  a cornercorner with one P(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 54-66°. The P(2)-O(1) bond length is 1.62 Å. The P(2)-O(2) bond length is 1.63 Å. The P(2)-O(5) bond length is 1.50 Å. The P(2)-O(6) bond length is 1.52 Å. There are seven inequivalent O sites. In the first O site, O(10) is bonded in a bent 120 degrees geometry to two equivalent K(2) atoms. In the second O site, O(1) is bonded in a bent 120 degrees geometry to one P(1) and one P(2) atom. In the third O site, O(2) is bonded in a distorted bent 150 degrees geometry to two equivalent P(2) atoms. In the fourth O site, O(3) is bonded in a distorted single-bond geometry to one K(2), two equivalent K(1), and one P(1) atom. In the fifth O site, O(4) is bonded in a distorted single-bond geometry to two equivalent K(1) and one P(1) atom. In the sixth O site, O(5) is bonded in a distorted bent 120 degrees geometry to one K(2) and one P(2) atom. In the seventh O site, O(6) is bonded in a distorted single-bond geometry to one K(1), one K(2), and one P(2) atom.