Zn2(OH)PO4 crystallizes in the triclinic P-1 space group. There are two inequivalent Zn sites. In the first Zn site, Zn(1) is bonded to one O(4), two equivalent O(3), and two equivalent O(5) atoms to form ZnO5 trigonal bipyramids that share corners with three equivalent P(1)O4 tetrahedra, corners with three equivalent Zn(2)O5 trigonal bipyramids, and edges with two equivalent Zn(1)O5 trigonal bipyramids. In the second Zn site, Zn(2) is bonded to one O(1), one O(4), one O(5), and two equivalent O(2) atoms to form ZnO5 trigonal bipyramids that share corners with four equivalent P(1)O4 tetrahedra, corners with three equivalent Zn(1)O5 trigonal bipyramids, and  an edgeedge with one Zn(2)O5 trigonal bipyramid. 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 three equivalent Zn(1)O5 trigonal bipyramids and corners with four equivalent Zn(2)O5 trigonal bipyramids. H(1) is bonded in a single-bond geometry to one O(5) atom. There are five inequivalent O sites. In the first O site, O(1) is bonded in a bent 120 degrees geometry to one Zn(2) and one P(1) atom. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to two equivalent Zn(2) and one P(1) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to two equivalent Zn(1) and one P(1) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Zn(1), one Zn(2), and one P(1) atom. In the fifth O site, O(5) is bonded in a distorted single-bond geometry to one Zn(2), two equivalent Zn(1), and one H(1) atom.
Zn2(OH)PO4 crystallizes in the triclinic P-1 space group. There are two inequivalent Zn sites. In the first Zn site, Zn(1) is bonded to one O(4), two equivalent O(3), and two equivalent O(5) atoms to form ZnO5 trigonal bipyramids that share corners with three equivalent P(1)O4 tetrahedra, corners with three equivalent Zn(2)O5 trigonal bipyramids, and edges with two equivalent Zn(1)O5 trigonal bipyramids. The Zn(1)-O(4) bond length is 1.99 Å. There is one shorter (2.04 Å) and one longer (2.18 Å) Zn(1)-O(3) bond length. There is one shorter (2.02 Å) and one longer (2.18 Å) Zn(1)-O(5) bond length. In the second Zn site, Zn(2) is bonded to one O(1), one O(4), one O(5), and two equivalent O(2) atoms to form ZnO5 trigonal bipyramids that share corners with four equivalent P(1)O4 tetrahedra, corners with three equivalent Zn(1)O5 trigonal bipyramids, and  an edgeedge with one Zn(2)O5 trigonal bipyramid. The Zn(2)-O(1) bond length is 2.00 Å. The Zn(2)-O(4) bond length is 2.22 Å. The Zn(2)-O(5) bond length is 2.02 Å. There is one shorter (2.04 Å) and one longer (2.14 Å) Zn(2)-O(2) bond length. 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 three equivalent Zn(1)O5 trigonal bipyramids and corners with four equivalent Zn(2)O5 trigonal bipyramids. The P(1)-O(1) bond length is 1.54 Å. The P(1)-O(2) bond length is 1.56 Å. The P(1)-O(3) bond length is 1.57 Å. The P(1)-O(4) bond length is 1.56 Å. H(1) is bonded in a single-bond geometry to one O(5) atom. The H(1)-O(5) bond length is 0.98 Å. There are five inequivalent O sites. In the first O site, O(1) is bonded in a bent 120 degrees geometry to one Zn(2) and one P(1) atom. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to two equivalent Zn(2) and one P(1) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to two equivalent Zn(1) and one P(1) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Zn(1), one Zn(2), and one P(1) atom. In the fifth O site, O(5) is bonded in a distorted single-bond geometry to one Zn(2), two equivalent Zn(1), and one H(1) atom.