SrFeSn(PO4)3 crystallizes in the trigonal R-3 space group. There are two inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a hexagonal planar geometry to six equivalent O(2) atoms. In the second Sr site, Sr(2) is bonded in a distorted hexagonal planar geometry to six equivalent O(1) atoms. Fe(1) is bonded to three equivalent O(2) and three equivalent O(4) atoms to form FeO6 octahedra that share corners with six equivalent P(1)O4 tetrahedra. Sn(1) is bonded to three equivalent O(1) and three equivalent O(3) atoms to form SnO6 octahedra that share corners with six equivalent P(1)O4 tetrahedra. 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 two equivalent Fe(1)O6 octahedra and corners with two equivalent Sn(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 34-38°. There are four inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Sr(2), one Sn(1), and one P(1) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Sr(1), one Fe(1), and one P(1) atom. In the third O site, O(3) is bonded in a bent 150 degrees geometry to one Sn(1) and one P(1) atom. In the fourth O site, O(4) is bonded in a bent 150 degrees geometry to one Fe(1) and one P(1) atom.
SrFeSn(PO4)3 crystallizes in the trigonal R-3 space group. There are two inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a hexagonal planar geometry to six equivalent O(2) atoms. All Sr(1)-O(2) bond lengths are 2.66 Å. In the second Sr site, Sr(2) is bonded in a distorted hexagonal planar geometry to six equivalent O(1) atoms. All Sr(2)-O(1) bond lengths are 2.59 Å. Fe(1) is bonded to three equivalent O(2) and three equivalent O(4) atoms to form FeO6 octahedra that share corners with six equivalent P(1)O4 tetrahedra. All Fe(1)-O(2) bond lengths are 2.06 Å. All Fe(1)-O(4) bond lengths are 1.99 Å. Sn(1) is bonded to three equivalent O(1) and three equivalent O(3) atoms to form SnO6 octahedra that share corners with six equivalent P(1)O4 tetrahedra. All Sn(1)-O(1) bond lengths are 2.09 Å. All Sn(1)-O(3) bond lengths are 2.03 Å. 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 two equivalent Fe(1)O6 octahedra and corners with two equivalent Sn(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 34-38°. The P(1)-O(1) bond length is 1.57 Å. The P(1)-O(2) bond length is 1.54 Å. The P(1)-O(3) bond length is 1.56 Å. The P(1)-O(4) bond length is 1.53 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Sr(2), one Sn(1), and one P(1) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Sr(1), one Fe(1), and one P(1) atom. In the third O site, O(3) is bonded in a bent 150 degrees geometry to one Sn(1) and one P(1) atom. In the fourth O site, O(4) is bonded in a bent 150 degrees geometry to one Fe(1) and one P(1) atom.