CsFeP(H6O5)2 crystallizes in the monoclinic C2 space group. Cs(1) is bonded to two equivalent O(1), two equivalent O(4), four equivalent O(2), and four equivalent O(3) atoms to form distorted CsO12 cuboctahedra that share corners with twelve equivalent Cs(1)O12 cuboctahedra and faces with four equivalent Fe(1)O6 octahedra. Fe(1) is bonded to one O(1), one O(4), two equivalent O(2), and two equivalent O(3) atoms to form FeO6 octahedra that share faces with four equivalent Cs(1)O12 cuboctahedra. P(1) is bonded in a tetrahedral geometry to two equivalent O(5) and two equivalent O(6) atoms. There are six inequivalent H sites. In the first H site, H(1) is bonded in a distorted linear geometry to one O(1) and one O(5) atom. In the second H site, H(2) is bonded in a distorted linear geometry to one O(2) and one O(6) atom. In the third H site, H(3) is bonded in a distorted linear geometry to one O(3) and one O(6) atom. In the fourth H site, H(4) is bonded in a distorted linear geometry to one O(4) and one O(6) atom. In the fifth H site, H(5) is bonded in a distorted linear geometry to one O(2) and one O(5) atom. In the sixth H site, H(6) is bonded in a distorted linear geometry to one O(3) and one O(5) atom. There are six inequivalent O sites. In the first O site, O(3) is bonded in a distorted trigonal planar geometry to two equivalent Cs(1), one Fe(1), one H(3), and one H(6) atom. In the second O site, O(4) is bonded in a distorted trigonal planar geometry to two equivalent Cs(1), one Fe(1), and two equivalent H(4) atoms. In the third O site, O(5) is bonded to one P(1), one H(1), one H(5), and one H(6) atom to form distorted corner-sharing OPH3 tetrahedra. In the fourth O site, O(6) is bonded to one P(1), one H(2), one H(3), and one H(4) atom to form distorted corner-sharing OPH3 tetrahedra. In the fifth O site, O(1) is bonded in a distorted bent 120 degrees geometry to two equivalent Cs(1), one Fe(1), and two equivalent H(1) atoms. In the sixth O site, O(2) is bonded in a distorted trigonal planar geometry to two equivalent Cs(1), one Fe(1), one H(2), and one H(5) atom.
CsFeP(H6O5)2 crystallizes in the monoclinic C2 space group. Cs(1) is bonded to two equivalent O(1), two equivalent O(4), four equivalent O(2), and four equivalent O(3) atoms to form distorted CsO12 cuboctahedra that share corners with twelve equivalent Cs(1)O12 cuboctahedra and faces with four equivalent Fe(1)O6 octahedra. Both Cs(1)-O(1) bond lengths are 3.60 Å. Both Cs(1)-O(4) bond lengths are 3.62 Å. There are two shorter (3.61 Å) and two longer (3.63 Å) Cs(1)-O(2) bond lengths. There are two shorter (3.61 Å) and two longer (3.62 Å) Cs(1)-O(3) bond lengths. Fe(1) is bonded to one O(1), one O(4), two equivalent O(2), and two equivalent O(3) atoms to form FeO6 octahedra that share faces with four equivalent Cs(1)O12 cuboctahedra. The Fe(1)-O(1) bond length is 2.18 Å. The Fe(1)-O(4) bond length is 2.14 Å. Both Fe(1)-O(2) bond lengths are 2.14 Å. Both Fe(1)-O(3) bond lengths are 2.15 Å. P(1) is bonded in a tetrahedral geometry to two equivalent O(5) and two equivalent O(6) atoms. Both P(1)-O(5) bond lengths are 1.56 Å. Both P(1)-O(6) bond lengths are 1.56 Å. There are six inequivalent H sites. In the first H site, H(1) is bonded in a distorted linear geometry to one O(1) and one O(5) atom. The H(1)-O(1) bond length is 1.00 Å. The H(1)-O(5) bond length is 1.66 Å. In the second H site, H(2) is bonded in a distorted linear geometry to one O(2) and one O(6) atom. The H(2)-O(2) bond length is 1.00 Å. The H(2)-O(6) bond length is 1.66 Å. In the third H site, H(3) is bonded in a distorted linear geometry to one O(3) and one O(6) atom. The H(3)-O(3) bond length is 1.00 Å. The H(3)-O(6) bond length is 1.65 Å. In the fourth H site, H(4) is bonded in a distorted linear geometry to one O(4) and one O(6) atom. The H(4)-O(4) bond length is 1.00 Å. The H(4)-O(6) bond length is 1.64 Å. In the fifth H site, H(5) is bonded in a distorted linear geometry to one O(2) and one O(5) atom. The H(5)-O(2) bond length is 1.00 Å. The H(5)-O(5) bond length is 1.66 Å. In the sixth H site, H(6) is bonded in a distorted linear geometry to one O(3) and one O(5) atom. The H(6)-O(3) bond length is 1.00 Å. The H(6)-O(5) bond length is 1.65 Å. There are six inequivalent O sites. In the first O site, O(3) is bonded in a distorted trigonal planar geometry to two equivalent Cs(1), one Fe(1), one H(3), and one H(6) atom. In the second O site, O(4) is bonded in a distorted trigonal planar geometry to two equivalent Cs(1), one Fe(1), and two equivalent H(4) atoms. In the third O site, O(5) is bonded to one P(1), one H(1), one H(5), and one H(6) atom to form distorted corner-sharing OPH3 tetrahedra. In the fourth O site, O(6) is bonded to one P(1), one H(2), one H(3), and one H(4) atom to form distorted corner-sharing OPH3 tetrahedra. In the fifth O site, O(1) is bonded in a distorted bent 120 degrees geometry to two equivalent Cs(1), one Fe(1), and two equivalent H(1) atoms. In the sixth O site, O(2) is bonded in a distorted trigonal planar geometry to two equivalent Cs(1), one Fe(1), one H(2), and one H(5) atom.