RbZnPO4 crystallizes in the monoclinic P2_1 space group. There are two inequivalent Rb sites. In the first Rb site, Rb(1) is bonded to one O(5), one O(6), two equivalent O(2), two equivalent O(3), and two equivalent O(7) atoms to form distorted RbO8 hexagonal bipyramids that share corners with two equivalent Rb(1)O8 hexagonal bipyramids, corners with two equivalent Zn(1)O4 tetrahedra, corners with two equivalent Zn(2)O4 tetrahedra, corners with two equivalent P(1)O4 tetrahedra, corners with two equivalent P(2)O4 tetrahedra, edges with two equivalent Rb(1)O8 hexagonal bipyramids,  an edgeedge with one Zn(1)O4 tetrahedra,  an edgeedge with one Zn(2)O4 tetrahedra,  an edgeedge with one P(1)O4 tetrahedra, and  an edgeedge with one P(2)O4 tetrahedra. In the second Rb site, Rb(2) is bonded in a 5-coordinate geometry to one O(1), one O(4), one O(5), one O(6), and one O(8) atom. There are two inequivalent Zn sites. In the first Zn site, Zn(1) is bonded to one O(1), one O(5), one O(6), and one O(7) atom to form ZnO4 tetrahedra that share corners with two equivalent Rb(1)O8 hexagonal bipyramids,  a cornercorner with one P(2)O4 tetrahedra, corners with three equivalent P(1)O4 tetrahedra, and  an edgeedge with one Rb(1)O8 hexagonal bipyramid. In the second Zn site, Zn(2) is bonded to one O(2), one O(3), one O(4), and one O(8) atom to form ZnO4 tetrahedra that share corners with two equivalent Rb(1)O8 hexagonal bipyramids,  a cornercorner with one P(1)O4 tetrahedra, corners with three equivalent P(2)O4 tetrahedra, and  an edgeedge with one Rb(1)O8 hexagonal bipyramid. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(5), one O(6), one O(7), and one O(8) atom to form PO4 tetrahedra that share corners with two equivalent Rb(1)O8 hexagonal bipyramids,  a cornercorner with one Zn(2)O4 tetrahedra, corners with three equivalent Zn(1)O4 tetrahedra, and  an edgeedge with one Rb(1)O8 hexagonal bipyramid. In the second P site, P(2) 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 Rb(1)O8 hexagonal bipyramids,  a cornercorner with one Zn(1)O4 tetrahedra, corners with three equivalent Zn(2)O4 tetrahedra, and  an edgeedge with one Rb(1)O8 hexagonal bipyramid. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a 2-coordinate geometry to one Rb(2), one Zn(1), and one P(2) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to two equivalent Rb(1), one Zn(2), and one P(2) atom. In the third O site, O(3) is bonded in a 2-coordinate geometry to two equivalent Rb(1), one Zn(2), and one P(2) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one Rb(2), one Zn(2), and one P(2) atom. In the fifth O site, O(5) is bonded in a 2-coordinate geometry to one Rb(1), one Rb(2), one Zn(1), and one P(1) atom. In the sixth O site, O(6) is bonded in a 2-coordinate geometry to one Rb(1), one Rb(2), one Zn(1), and one P(1) atom. In the seventh O site, O(7) is bonded in a 2-coordinate geometry to two equivalent Rb(1), one Zn(1), and one P(1) atom. In the eighth O site, O(8) is bonded in a 2-coordinate geometry to one Rb(2), one Zn(2), and one P(1) atom.
RbZnPO4 crystallizes in the monoclinic P2_1 space group. There are two inequivalent Rb sites. In the first Rb site, Rb(1) is bonded to one O(5), one O(6), two equivalent O(2), two equivalent O(3), and two equivalent O(7) atoms to form distorted RbO8 hexagonal bipyramids that share corners with two equivalent Rb(1)O8 hexagonal bipyramids, corners with two equivalent Zn(1)O4 tetrahedra, corners with two equivalent Zn(2)O4 tetrahedra, corners with two equivalent P(1)O4 tetrahedra, corners with two equivalent P(2)O4 tetrahedra, edges with two equivalent Rb(1)O8 hexagonal bipyramids,  an edgeedge with one Zn(1)O4 tetrahedra,  an edgeedge with one Zn(2)O4 tetrahedra,  an edgeedge with one P(1)O4 tetrahedra, and  an edgeedge with one P(2)O4 tetrahedra. The Rb(1)-O(5) bond length is 3.16 Å. The Rb(1)-O(6) bond length is 3.25 Å. There is one shorter (2.90 Å) and one longer (3.03 Å) Rb(1)-O(2) bond length. There is one shorter (2.88 Å) and one longer (3.11 Å) Rb(1)-O(3) bond length. There is one shorter (2.96 Å) and one longer (3.19 Å) Rb(1)-O(7) bond length. In the second Rb site, Rb(2) is bonded in a 5-coordinate geometry to one O(1), one O(4), one O(5), one O(6), and one O(8) atom. The Rb(2)-O(1) bond length is 3.03 Å. The Rb(2)-O(4) bond length is 2.94 Å. The Rb(2)-O(5) bond length is 2.97 Å. The Rb(2)-O(6) bond length is 3.01 Å. The Rb(2)-O(8) bond length is 3.00 Å. There are two inequivalent Zn sites. In the first Zn site, Zn(1) is bonded to one O(1), one O(5), one O(6), and one O(7) atom to form ZnO4 tetrahedra that share corners with two equivalent Rb(1)O8 hexagonal bipyramids,  a cornercorner with one P(2)O4 tetrahedra, corners with three equivalent P(1)O4 tetrahedra, and  an edgeedge with one Rb(1)O8 hexagonal bipyramid. The Zn(1)-O(1) bond length is 1.97 Å. The Zn(1)-O(5) bond length is 1.99 Å. The Zn(1)-O(6) bond length is 1.98 Å. The Zn(1)-O(7) bond length is 1.97 Å. In the second Zn site, Zn(2) is bonded to one O(2), one O(3), one O(4), and one O(8) atom to form ZnO4 tetrahedra that share corners with two equivalent Rb(1)O8 hexagonal bipyramids,  a cornercorner with one P(1)O4 tetrahedra, corners with three equivalent P(2)O4 tetrahedra, and  an edgeedge with one Rb(1)O8 hexagonal bipyramid. The Zn(2)-O(2) bond length is 1.98 Å. The Zn(2)-O(3) bond length is 1.99 Å. The Zn(2)-O(4) bond length is 1.95 Å. The Zn(2)-O(8) bond length is 1.96 Å. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(5), one O(6), one O(7), and one O(8) atom to form PO4 tetrahedra that share corners with two equivalent Rb(1)O8 hexagonal bipyramids,  a cornercorner with one Zn(2)O4 tetrahedra, corners with three equivalent Zn(1)O4 tetrahedra, and  an edgeedge with one Rb(1)O8 hexagonal bipyramid. The P(1)-O(5) bond length is 1.56 Å. The P(1)-O(6) bond length is 1.56 Å. The P(1)-O(7) bond length is 1.56 Å. The P(1)-O(8) bond length is 1.56 Å. In the second P site, P(2) 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 Rb(1)O8 hexagonal bipyramids,  a cornercorner with one Zn(1)O4 tetrahedra, corners with three equivalent Zn(2)O4 tetrahedra, and  an edgeedge with one Rb(1)O8 hexagonal bipyramid. The P(2)-O(1) bond length is 1.55 Å. The P(2)-O(2) bond length is 1.56 Å. The P(2)-O(3) bond length is 1.56 Å. The P(2)-O(4) bond length is 1.54 Å. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a 2-coordinate geometry to one Rb(2), one Zn(1), and one P(2) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to two equivalent Rb(1), one Zn(2), and one P(2) atom. In the third O site, O(3) is bonded in a 2-coordinate geometry to two equivalent Rb(1), one Zn(2), and one P(2) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one Rb(2), one Zn(2), and one P(2) atom. In the fifth O site, O(5) is bonded in a 2-coordinate geometry to one Rb(1), one Rb(2), one Zn(1), and one P(1) atom. In the sixth O site, O(6) is bonded in a 2-coordinate geometry to one Rb(1), one Rb(2), one Zn(1), and one P(1) atom. In the seventh O site, O(7) is bonded in a 2-coordinate geometry to two equivalent Rb(1), one Zn(1), and one P(1) atom. In the eighth O site, O(8) is bonded in a 2-coordinate geometry to one Rb(2), one Zn(2), and one P(1) atom.