NaFe7(PO4)6 crystallizes in the triclinic P-1 space group. Na(1) is bonded in a 4-coordinate geometry to two equivalent P(1) and two equivalent O(1) atoms. There are four inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in a 5-coordinate geometry to one O(4), one O(5), one O(6), one O(7), and one O(8) atom. In the second Fe site, Fe(2) is bonded to one O(1), one O(10), one O(5), and one O(7) atom to form FeO4 tetrahedra that share  a cornercorner with one P(2)O4 tetrahedra and  a cornercorner with one P(3)O4 tetrahedra. In the third Fe site, Fe(3) is bonded to one O(11), one O(9), and two equivalent O(2) atoms to form distorted FeO4 trigonal pyramids that share  a cornercorner with one P(2)O4 tetrahedra,  a cornercorner with one P(3)O4 tetrahedra, and  an edgeedge with one Fe(3)O4 trigonal pyramid. In the fourth Fe site, Fe(4) is bonded in a square co-planar geometry to two equivalent O(11) and two equivalent O(3) atoms. There are three inequivalent P sites. In the first P site, P(1) is bonded in a 3-coordinate geometry to one Na(1), one O(12), one O(2), and one O(6) atom. In the second P site, P(2) is bonded to one O(1), one O(11), one O(12), and one O(8) atom to form PO4 tetrahedra that share  a cornercorner with one Fe(2)O4 tetrahedra and  a cornercorner with one Fe(3)O4 trigonal pyramid. In the third P site, P(3) is bonded to one O(10), one O(3), one O(4), and one O(9) atom to form PO4 tetrahedra that share  a cornercorner with one Fe(2)O4 tetrahedra and  a cornercorner with one Fe(3)O4 trigonal pyramid. There are twelve inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Na(1), one Fe(2), and one P(2) atom. In the second O site, O(2) is bonded in a trigonal non-coplanar geometry to two equivalent Fe(3) and one P(1) atom. In the third O site, O(3) is bonded in a distorted bent 150 degrees geometry to one Fe(4) and one P(3) atom. In the fourth O site, O(4) is bonded in a distorted bent 150 degrees geometry to one Fe(1) and one P(3) atom. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to one Fe(1), one Fe(2), and one O(7) atom. In the sixth O site, O(6) is bonded in a bent 150 degrees geometry to one Fe(1) and one P(1) atom. In the seventh O site, O(7) is bonded in a 3-coordinate geometry to one Fe(1), one Fe(2), and one O(5) atom. In the eighth O site, O(8) is bonded in a distorted bent 150 degrees geometry to one Fe(1) and one P(2) atom. In the ninth O site, O(9) is bonded in a bent 150 degrees geometry to one Fe(3) and one P(3) atom. In the tenth O site, O(10) is bonded in a distorted bent 150 degrees geometry to one Fe(2) and one P(3) atom. In the eleventh O site, O(11) is bonded in a distorted trigonal planar geometry to one Fe(3), one Fe(4), and one P(2) atom. In the twelfth O site, O(12) is bonded in a bent 120 degrees geometry to one P(1) and one P(2) atom.
NaFe7(PO4)6 crystallizes in the triclinic P-1 space group. Na(1) is bonded in a 4-coordinate geometry to two equivalent P(1) and two equivalent O(1) atoms. Both Na(1)-P(1) bond lengths are 2.95 Å. Both Na(1)-O(1) bond lengths are 2.79 Å. There are four inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in a 5-coordinate geometry to one O(4), one O(5), one O(6), one O(7), and one O(8) atom. The Fe(1)-O(4) bond length is 1.89 Å. The Fe(1)-O(5) bond length is 1.98 Å. The Fe(1)-O(6) bond length is 1.90 Å. The Fe(1)-O(7) bond length is 2.12 Å. The Fe(1)-O(8) bond length is 1.99 Å. In the second Fe site, Fe(2) is bonded to one O(1), one O(10), one O(5), and one O(7) atom to form FeO4 tetrahedra that share  a cornercorner with one P(2)O4 tetrahedra and  a cornercorner with one P(3)O4 tetrahedra. The Fe(2)-O(1) bond length is 1.98 Å. The Fe(2)-O(10) bond length is 1.88 Å. The Fe(2)-O(5) bond length is 1.99 Å. The Fe(2)-O(7) bond length is 1.94 Å. In the third Fe site, Fe(3) is bonded to one O(11), one O(9), and two equivalent O(2) atoms to form distorted FeO4 trigonal pyramids that share  a cornercorner with one P(2)O4 tetrahedra,  a cornercorner with one P(3)O4 tetrahedra, and  an edgeedge with one Fe(3)O4 trigonal pyramid. The Fe(3)-O(11) bond length is 2.14 Å. The Fe(3)-O(9) bond length is 1.92 Å. There is one shorter (2.04 Å) and one longer (2.13 Å) Fe(3)-O(2) bond length. In the fourth Fe site, Fe(4) is bonded in a square co-planar geometry to two equivalent O(11) and two equivalent O(3) atoms. Both Fe(4)-O(11) bond lengths are 2.23 Å. Both Fe(4)-O(3) bond lengths are 1.95 Å. There are three inequivalent P sites. In the first P site, P(1) is bonded in a 3-coordinate geometry to one Na(1), one O(12), one O(2), and one O(6) atom. The P(1)-O(12) bond length is 1.76 Å. The P(1)-O(2) bond length is 1.60 Å. The P(1)-O(6) bond length is 1.58 Å. In the second P site, P(2) is bonded to one O(1), one O(11), one O(12), and one O(8) atom to form PO4 tetrahedra that share  a cornercorner with one Fe(2)O4 tetrahedra and  a cornercorner with one Fe(3)O4 trigonal pyramid. The P(2)-O(1) bond length is 1.55 Å. The P(2)-O(11) bond length is 1.57 Å. The P(2)-O(12) bond length is 1.60 Å. The P(2)-O(8) bond length is 1.53 Å. In the third P site, P(3) is bonded to one O(10), one O(3), one O(4), and one O(9) atom to form PO4 tetrahedra that share  a cornercorner with one Fe(2)O4 tetrahedra and  a cornercorner with one Fe(3)O4 trigonal pyramid. The P(3)-O(10) bond length is 1.55 Å. The P(3)-O(3) bond length is 1.55 Å. The P(3)-O(4) bond length is 1.56 Å. The P(3)-O(9) bond length is 1.53 Å. There are twelve inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Na(1), one Fe(2), and one P(2) atom. In the second O site, O(2) is bonded in a trigonal non-coplanar geometry to two equivalent Fe(3) and one P(1) atom. In the third O site, O(3) is bonded in a distorted bent 150 degrees geometry to one Fe(4) and one P(3) atom. In the fourth O site, O(4) is bonded in a distorted bent 150 degrees geometry to one Fe(1) and one P(3) atom. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to one Fe(1), one Fe(2), and one O(7) atom. The O(5)-O(7) bond length is 1.52 Å. In the sixth O site, O(6) is bonded in a bent 150 degrees geometry to one Fe(1) and one P(1) atom. In the seventh O site, O(7) is bonded in a 3-coordinate geometry to one Fe(1), one Fe(2), and one O(5) atom. In the eighth O site, O(8) is bonded in a distorted bent 150 degrees geometry to one Fe(1) and one P(2) atom. In the ninth O site, O(9) is bonded in a bent 150 degrees geometry to one Fe(3) and one P(3) atom. In the tenth O site, O(10) is bonded in a distorted bent 150 degrees geometry to one Fe(2) and one P(3) atom. In the eleventh O site, O(11) is bonded in a distorted trigonal planar geometry to one Fe(3), one Fe(4), and one P(2) atom. In the twelfth O site, O(12) is bonded in a bent 120 degrees geometry to one P(1) and one P(2) atom.