Na4Ni(PO4)6 crystallizes in the triclinic P-1 space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded to one O(2), one O(5), one O(6), one O(9), and two equivalent O(1) atoms to form NaO6 octahedra that share  a cornercorner with one P(3)O4 tetrahedra, corners with two equivalent P(2)O4 tetrahedra, corners with three equivalent P(1)O4 tetrahedra,  an edgeedge with one Na(1)O6 octahedra, and edges with two equivalent Na(2)O6 octahedra. In the second Na site, Na(2) is bonded to one O(1), one O(10), one O(6), one O(9), and two equivalent O(8) atoms to form distorted NaO6 octahedra that share  a cornercorner with one Ni(1)O6 octahedra,  a cornercorner with one P(1)O4 tetrahedra,  a cornercorner with one P(2)O4 tetrahedra, corners with three equivalent P(3)O4 tetrahedra,  an edgeedge with one Na(2)O6 octahedra, and edges with two equivalent Na(1)O6 octahedra. The corner-sharing octahedral tilt angles are 46°. Ni(1) is bonded to two equivalent O(10), two equivalent O(11), and two equivalent O(12) atoms to form NiO6 octahedra that share corners with two equivalent Na(2)O6 octahedra. The corner-sharing octahedral tilt angles are 46°. There are three 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(4) atom to form PO4 tetrahedra that share  a cornercorner with one Na(2)O6 octahedra, corners with three equivalent Na(1)O6 octahedra,  a cornercorner with one P(2)O4 tetrahedra, and  a cornercorner with one P(3)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 48-63°. In the second P site, P(2) is bonded to one O(3), one O(5), one O(6), and one O(7) atom to form PO4 tetrahedra that share  a cornercorner with one Na(2)O6 octahedra, corners with two equivalent Na(1)O6 octahedra,  a cornercorner with one P(1)O4 tetrahedra, and  a cornercorner with one P(3)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 53-65°. In the third P site, P(3) is bonded to one O(4), one O(7), one O(8), and one O(9) atom to form PO4 tetrahedra that share  a cornercorner with one Na(1)O6 octahedra, corners with three equivalent Na(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 48-60°. There are twelve inequivalent O sites. In the first O site, O(12) is bonded in a single-bond geometry to one Ni(1) atom. In the second O site, O(1) is bonded in a distorted rectangular see-saw-like geometry to one Na(2), two equivalent Na(1), and one P(1) atom. In the third O site, O(2) is bonded in a bent 120 degrees geometry to one Na(1) and one P(1) atom. In the fourth O site, O(3) is bonded in a bent 120 degrees geometry to one P(1) and one P(2) atom. In the fifth O site, O(4) is bonded in a bent 120 degrees geometry to one P(1) and one P(3) atom. In the sixth O site, O(5) is bonded in a bent 120 degrees geometry to one Na(1) and one P(2) atom. In the seventh O site, O(6) is bonded in a 3-coordinate geometry to one Na(1), one Na(2), and one P(2) atom. In the eighth O site, O(7) is bonded in a bent 120 degrees geometry to one P(2) and one P(3) atom. In the ninth O site, O(8) is bonded in a distorted trigonal planar geometry to two equivalent Na(2) and one P(3) atom. In the tenth O site, O(9) is bonded in a distorted trigonal planar geometry to one Na(1), one Na(2), and one P(3) atom. In the eleventh O site, O(10) is bonded in a distorted single-bond geometry to one Na(2) and one Ni(1) atom. In the twelfth O site, O(11) is bonded in a single-bond geometry to one Ni(1) atom.
Na4Ni(PO4)6 crystallizes in the triclinic P-1 space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded to one O(2), one O(5), one O(6), one O(9), and two equivalent O(1) atoms to form NaO6 octahedra that share  a cornercorner with one P(3)O4 tetrahedra, corners with two equivalent P(2)O4 tetrahedra, corners with three equivalent P(1)O4 tetrahedra,  an edgeedge with one Na(1)O6 octahedra, and edges with two equivalent Na(2)O6 octahedra. The Na(1)-O(2) bond length is 2.46 Å. The Na(1)-O(5) bond length is 2.36 Å. The Na(1)-O(6) bond length is 2.76 Å. The Na(1)-O(9) bond length is 2.33 Å. There is one shorter (2.46 Å) and one longer (2.72 Å) Na(1)-O(1) bond length. In the second Na site, Na(2) is bonded to one O(1), one O(10), one O(6), one O(9), and two equivalent O(8) atoms to form distorted NaO6 octahedra that share  a cornercorner with one Ni(1)O6 octahedra,  a cornercorner with one P(1)O4 tetrahedra,  a cornercorner with one P(2)O4 tetrahedra, corners with three equivalent P(3)O4 tetrahedra,  an edgeedge with one Na(2)O6 octahedra, and edges with two equivalent Na(1)O6 octahedra. The corner-sharing octahedral tilt angles are 46°. The Na(2)-O(1) bond length is 2.41 Å. The Na(2)-O(10) bond length is 2.71 Å. The Na(2)-O(6) bond length is 2.47 Å. The Na(2)-O(9) bond length is 2.37 Å. There is one shorter (2.34 Å) and one longer (2.42 Å) Na(2)-O(8) bond length. Ni(1) is bonded to two equivalent O(10), two equivalent O(11), and two equivalent O(12) atoms to form NiO6 octahedra that share corners with two equivalent Na(2)O6 octahedra. The corner-sharing octahedral tilt angles are 46°. Both Ni(1)-O(10) bond lengths are 1.78 Å. Both Ni(1)-O(11) bond lengths are 1.79 Å. Both Ni(1)-O(12) bond lengths are 2.09 Å. There are three 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(4) atom to form PO4 tetrahedra that share  a cornercorner with one Na(2)O6 octahedra, corners with three equivalent Na(1)O6 octahedra,  a cornercorner with one P(2)O4 tetrahedra, and  a cornercorner with one P(3)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 48-63°. The P(1)-O(1) bond length is 1.50 Å. The P(1)-O(2) bond length is 1.51 Å. The P(1)-O(3) bond length is 1.64 Å. The P(1)-O(4) bond length is 1.63 Å. In the second P site, P(2) is bonded to one O(3), one O(5), one O(6), and one O(7) atom to form PO4 tetrahedra that share  a cornercorner with one Na(2)O6 octahedra, corners with two equivalent Na(1)O6 octahedra,  a cornercorner with one P(1)O4 tetrahedra, and  a cornercorner with one P(3)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 53-65°. The P(2)-O(3) bond length is 1.62 Å. The P(2)-O(5) bond length is 1.50 Å. The P(2)-O(6) bond length is 1.53 Å. The P(2)-O(7) bond length is 1.61 Å. In the third P site, P(3) is bonded to one O(4), one O(7), one O(8), and one O(9) atom to form PO4 tetrahedra that share  a cornercorner with one Na(1)O6 octahedra, corners with three equivalent Na(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 48-60°. The P(3)-O(4) bond length is 1.64 Å. The P(3)-O(7) bond length is 1.64 Å. The P(3)-O(8) bond length is 1.50 Å. The P(3)-O(9) bond length is 1.49 Å. There are twelve inequivalent O sites. In the first O site, O(12) is bonded in a single-bond geometry to one Ni(1) atom. In the second O site, O(1) is bonded in a distorted rectangular see-saw-like geometry to one Na(2), two equivalent Na(1), and one P(1) atom. In the third O site, O(2) is bonded in a bent 120 degrees geometry to one Na(1) and one P(1) atom. In the fourth O site, O(3) is bonded in a bent 120 degrees geometry to one P(1) and one P(2) atom. In the fifth O site, O(4) is bonded in a bent 120 degrees geometry to one P(1) and one P(3) atom. In the sixth O site, O(5) is bonded in a bent 120 degrees geometry to one Na(1) and one P(2) atom. In the seventh O site, O(6) is bonded in a 3-coordinate geometry to one Na(1), one Na(2), and one P(2) atom. In the eighth O site, O(7) is bonded in a bent 120 degrees geometry to one P(2) and one P(3) atom. In the ninth O site, O(8) is bonded in a distorted trigonal planar geometry to two equivalent Na(2) and one P(3) atom. In the tenth O site, O(9) is bonded in a distorted trigonal planar geometry to one Na(1), one Na(2), and one P(3) atom. In the eleventh O site, O(10) is bonded in a distorted single-bond geometry to one Na(2) and one Ni(1) atom. In the twelfth O site, O(11) is bonded in a single-bond geometry to one Ni(1) atom.