NaFe9B3Si6H3O31 crystallizes in the trigonal R3m space group. Na(1) is bonded in a 9-coordinate geometry to three equivalent O(4), three equivalent O(6), and three equivalent O(8) atoms. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(1), one O(3), two equivalent O(2), and two equivalent O(5) atoms to form FeO6 octahedra that share  a cornercorner with one Fe(1)O6 octahedra, corners with three equivalent Si(1)O4 tetrahedra,  an edgeedge with one Fe(2)O6 octahedra, and edges with two equivalent Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles are 57°. In the second Fe site, Fe(2) is bonded to one O(1), one O(7), two equivalent O(3), and two equivalent O(8) atoms to form FeO6 octahedra that share corners with two equivalent Si(1)O4 tetrahedra, edges with two equivalent Fe(1)O6 octahedra, and edges with two equivalent Fe(2)O6 octahedra. B(1) is bonded in a trigonal planar geometry to one O(8) and two equivalent O(2) atoms. Si(1) is bonded to one O(3), one O(4), one O(5), and one O(6) atom to form SiO4 tetrahedra that share  a cornercorner with one Fe(2)O6 octahedra, corners with three equivalent Fe(1)O6 octahedra, and corners with two equivalent Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 46-57°. H(1) is bonded in a single-bond geometry to one O(1) atom. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a distorted single-bond geometry to one Fe(2), two equivalent Fe(1), and one H(1) atom. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to two equivalent Fe(1) and one B(1) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Fe(1), one Fe(2), and one Si(1) atom. In the fourth O site, O(4) is bonded in a 2-coordinate geometry to one Na(1) and two equivalent Si(1) atoms. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to two equivalent Fe(1) and one Si(1) atom. In the sixth O site, O(8) is bonded in a 4-coordinate geometry to one Na(1), two equivalent Fe(2), and one B(1) atom. In the seventh O site, O(6) is bonded in a distorted bent 150 degrees geometry to one Na(1) and two equivalent Si(1) atoms. In the eighth O site, O(7) is bonded in a distorted trigonal non-coplanar geometry to three equivalent Fe(2) atoms.
NaFe9B3Si6H3O31 crystallizes in the trigonal R3m space group. Na(1) is bonded in a 9-coordinate geometry to three equivalent O(4), three equivalent O(6), and three equivalent O(8) atoms. All Na(1)-O(4) bond lengths are 2.83 Å. All Na(1)-O(6) bond lengths are 2.89 Å. All Na(1)-O(8) bond lengths are 2.67 Å. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(1), one O(3), two equivalent O(2), and two equivalent O(5) atoms to form FeO6 octahedra that share  a cornercorner with one Fe(1)O6 octahedra, corners with three equivalent Si(1)O4 tetrahedra,  an edgeedge with one Fe(2)O6 octahedra, and edges with two equivalent Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles are 57°. The Fe(1)-O(1) bond length is 2.15 Å. The Fe(1)-O(3) bond length is 2.09 Å. There is one shorter (2.03 Å) and one longer (2.06 Å) Fe(1)-O(2) bond length. There is one shorter (2.04 Å) and one longer (2.07 Å) Fe(1)-O(5) bond length. In the second Fe site, Fe(2) is bonded to one O(1), one O(7), two equivalent O(3), and two equivalent O(8) atoms to form FeO6 octahedra that share corners with two equivalent Si(1)O4 tetrahedra, edges with two equivalent Fe(1)O6 octahedra, and edges with two equivalent Fe(2)O6 octahedra. The Fe(2)-O(1) bond length is 2.10 Å. The Fe(2)-O(7) bond length is 1.99 Å. Both Fe(2)-O(3) bond lengths are 2.04 Å. Both Fe(2)-O(8) bond lengths are 2.09 Å. B(1) is bonded in a trigonal planar geometry to one O(8) and two equivalent O(2) atoms. The B(1)-O(8) bond length is 1.41 Å. Both B(1)-O(2) bond lengths are 1.38 Å. Si(1) is bonded to one O(3), one O(4), one O(5), and one O(6) atom to form SiO4 tetrahedra that share  a cornercorner with one Fe(2)O6 octahedra, corners with three equivalent Fe(1)O6 octahedra, and corners with two equivalent Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 46-57°. The Si(1)-O(3) bond length is 1.63 Å. The Si(1)-O(4) bond length is 1.66 Å. The Si(1)-O(5) bond length is 1.62 Å. The Si(1)-O(6) bond length is 1.65 Å. H(1) is bonded in a single-bond geometry to one O(1) atom. The H(1)-O(1) bond length is 0.98 Å. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a distorted single-bond geometry to one Fe(2), two equivalent Fe(1), and one H(1) atom. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to two equivalent Fe(1) and one B(1) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Fe(1), one Fe(2), and one Si(1) atom. In the fourth O site, O(4) is bonded in a 2-coordinate geometry to one Na(1) and two equivalent Si(1) atoms. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to two equivalent Fe(1) and one Si(1) atom. In the sixth O site, O(8) is bonded in a 4-coordinate geometry to one Na(1), two equivalent Fe(2), and one B(1) atom. In the seventh O site, O(6) is bonded in a distorted bent 150 degrees geometry to one Na(1) and two equivalent Si(1) atoms. In the eighth O site, O(7) is bonded in a distorted trigonal non-coplanar geometry to three equivalent Fe(2) atoms.