BiNiPO5 crystallizes in the monoclinic P2_1/c space group. Ni(1) is bonded to one O(2), one O(3), one O(4), one O(5), and two equivalent O(1) atoms to form NiO6 octahedra that share corners with four equivalent P(1)O4 tetrahedra and  an edgeedge with one Ni(1)O6 octahedra. Bi(1) is bonded in a 6-coordinate geometry to one O(2), one O(3), one O(4), one O(5), and two equivalent O(1) atoms. P(1) is bonded to one O(2), one O(3), one O(4), and one O(5) atom to form PO4 tetrahedra that share corners with four equivalent Ni(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 25-49°. There are five inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Ni(1) and two equivalent Bi(1) atoms to form edge-sharing ONi2Bi2 tetrahedra. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Ni(1), one Bi(1), and one P(1) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Ni(1), one Bi(1), and one P(1) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one Ni(1), one Bi(1), and one P(1) atom. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to one Ni(1), one Bi(1), and one P(1) atom.
BiNiPO5 crystallizes in the monoclinic P2_1/c space group. Ni(1) is bonded to one O(2), one O(3), one O(4), one O(5), and two equivalent O(1) atoms to form NiO6 octahedra that share corners with four equivalent P(1)O4 tetrahedra and  an edgeedge with one Ni(1)O6 octahedra. The Ni(1)-O(2) bond length is 2.09 Å. The Ni(1)-O(3) bond length is 2.01 Å. The Ni(1)-O(4) bond length is 2.10 Å. The Ni(1)-O(5) bond length is 2.11 Å. There is one shorter (2.03 Å) and one longer (2.07 Å) Ni(1)-O(1) bond length. Bi(1) is bonded in a 6-coordinate geometry to one O(2), one O(3), one O(4), one O(5), and two equivalent O(1) atoms. The Bi(1)-O(2) bond length is 2.43 Å. The Bi(1)-O(3) bond length is 2.63 Å. The Bi(1)-O(4) bond length is 2.38 Å. The Bi(1)-O(5) bond length is 2.48 Å. There is one shorter (2.18 Å) and one longer (2.22 Å) Bi(1)-O(1) bond length. P(1) is bonded to one O(2), one O(3), one O(4), and one O(5) atom to form PO4 tetrahedra that share corners with four equivalent Ni(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 25-49°. 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 1.54 Å. The P(1)-O(5) bond length is 1.54 Å. There are five inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Ni(1) and two equivalent Bi(1) atoms to form edge-sharing ONi2Bi2 tetrahedra. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Ni(1), one Bi(1), and one P(1) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Ni(1), one Bi(1), and one P(1) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one Ni(1), one Bi(1), and one P(1) atom. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to one Ni(1), one Bi(1), and one P(1) atom.