Sr2MgZn2Sn2(PO4)4 crystallizes in the triclinic P-1 space group. Sr(1) is bonded to one O(2), one O(3), one O(8), two equivalent O(1), and two equivalent O(6) atoms to form distorted SrO7 pentagonal bipyramids that share corners with two equivalent P(1)O4 tetrahedra, corners with three equivalent P(2)O4 tetrahedra, edges with two equivalent Sr(1)O7 pentagonal bipyramids, and  an edgeedge with one P(1)O4 tetrahedra. Mg(1) is bonded in a distorted square co-planar geometry to two equivalent O(4) and two equivalent O(5) atoms. Zn(1) is bonded in a 3-coordinate geometry to one O(2), one O(4), and one O(7) atom. Sn(1) is bonded in a 3-coordinate geometry to one O(3), one O(5), and one O(7) atom. There are two 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(7) atom to form PO4 tetrahedra that share corners with two equivalent Sr(1)O7 pentagonal bipyramids and  an edgeedge with one Sr(1)O7 pentagonal bipyramid. In the second P site, P(2) is bonded to one O(4), one O(5), one O(6), and one O(8) atom to form PO4 tetrahedra that share corners with three equivalent Sr(1)O7 pentagonal bipyramids. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to two equivalent Sr(1) and one P(1) atom. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one Sr(1), one Zn(1), and one P(1) atom. In the third O site, O(3) is bonded in a 2-coordinate geometry to one Sr(1), one Sn(1), and one P(1) atom. In the fourth O site, O(4) is bonded in a distorted T-shaped geometry to one Mg(1), one Zn(1), and one P(2) atom. In the fifth O site, O(5) is bonded in a trigonal non-coplanar geometry to one Mg(1), one Sn(1), and one P(2) atom. In the sixth O site, O(6) is bonded in a 3-coordinate geometry to two equivalent Sr(1) and one P(2) atom. In the seventh O site, O(7) is bonded in a 3-coordinate geometry to one Zn(1), one Sn(1), and one P(1) atom. In the eighth O site, O(8) is bonded in a distorted bent 150 degrees geometry to one Sr(1) and one P(2) atom.
Sr2MgZn2Sn2(PO4)4 crystallizes in the triclinic P-1 space group. Sr(1) is bonded to one O(2), one O(3), one O(8), two equivalent O(1), and two equivalent O(6) atoms to form distorted SrO7 pentagonal bipyramids that share corners with two equivalent P(1)O4 tetrahedra, corners with three equivalent P(2)O4 tetrahedra, edges with two equivalent Sr(1)O7 pentagonal bipyramids, and  an edgeedge with one P(1)O4 tetrahedra. The Sr(1)-O(2) bond length is 2.63 Å. The Sr(1)-O(3) bond length is 2.90 Å. The Sr(1)-O(8) bond length is 2.47 Å. There is one shorter (2.51 Å) and one longer (2.68 Å) Sr(1)-O(1) bond length. There is one shorter (2.54 Å) and one longer (2.67 Å) Sr(1)-O(6) bond length. Mg(1) is bonded in a distorted square co-planar geometry to two equivalent O(4) and two equivalent O(5) atoms. Both Mg(1)-O(4) bond lengths are 2.00 Å. Both Mg(1)-O(5) bond lengths are 2.00 Å. Zn(1) is bonded in a 3-coordinate geometry to one O(2), one O(4), and one O(7) atom. The Zn(1)-O(2) bond length is 2.06 Å. The Zn(1)-O(4) bond length is 2.33 Å. The Zn(1)-O(7) bond length is 2.34 Å. Sn(1) is bonded in a 3-coordinate geometry to one O(3), one O(5), and one O(7) atom. The Sn(1)-O(3) bond length is 2.09 Å. The Sn(1)-O(5) bond length is 2.15 Å. The Sn(1)-O(7) bond length is 2.22 Å. There are two 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(7) atom to form PO4 tetrahedra that share corners with two equivalent Sr(1)O7 pentagonal bipyramids and  an edgeedge with one Sr(1)O7 pentagonal bipyramid. The P(1)-O(1) bond length is 1.52 Å. The P(1)-O(2) bond length is 1.55 Å. The P(1)-O(3) bond length is 1.59 Å. The P(1)-O(7) bond length is 1.59 Å. In the second P site, P(2) is bonded to one O(4), one O(5), one O(6), and one O(8) atom to form PO4 tetrahedra that share corners with three equivalent Sr(1)O7 pentagonal bipyramids. The P(2)-O(4) bond length is 1.58 Å. The P(2)-O(5) bond length is 1.64 Å. The P(2)-O(6) bond length is 1.53 Å. The P(2)-O(8) bond length is 1.52 Å. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to two equivalent Sr(1) and one P(1) atom. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one Sr(1), one Zn(1), and one P(1) atom. In the third O site, O(3) is bonded in a 2-coordinate geometry to one Sr(1), one Sn(1), and one P(1) atom. In the fourth O site, O(4) is bonded in a distorted T-shaped geometry to one Mg(1), one Zn(1), and one P(2) atom. In the fifth O site, O(5) is bonded in a trigonal non-coplanar geometry to one Mg(1), one Sn(1), and one P(2) atom. In the sixth O site, O(6) is bonded in a 3-coordinate geometry to two equivalent Sr(1) and one P(2) atom. In the seventh O site, O(7) is bonded in a 3-coordinate geometry to one Zn(1), one Sn(1), and one P(1) atom. In the eighth O site, O(8) is bonded in a distorted bent 150 degrees geometry to one Sr(1) and one P(2) atom.