Cs4Fe3F10 crystallizes in the orthorhombic Cmce space group. There are two inequivalent Cs sites. In the first Cs site, Cs(1) is bonded in a 11-coordinate geometry to one F(2), two equivalent F(4), four equivalent F(1), and four equivalent F(3) atoms. In the second Cs site, Cs(2) is bonded in a 10-coordinate geometry to one F(1), two equivalent F(4), three equivalent F(2), and four equivalent F(3) atoms. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one F(1), one F(2), two equivalent F(3), and two equivalent F(4) atoms to form a mixture of face and corner-sharing FeF6 octahedra. The corner-sharing octahedral tilt angles are 5°. In the second Fe site, Fe(2) is bonded to two equivalent F(2) and four equivalent F(3) atoms to form face-sharing FeF6 octahedra. There are four inequivalent F sites. In the first F site, F(4) is bonded in a distorted linear geometry to two equivalent Cs(1), two equivalent Cs(2), and two equivalent Fe(1) atoms. In the second F site, F(1) is bonded in a distorted single-bond geometry to one Cs(2), four equivalent Cs(1), and one Fe(1) atom. In the third F site, F(2) is bonded in a 2-coordinate geometry to one Cs(1), three equivalent Cs(2), one Fe(1), and one Fe(2) atom. In the fourth F site, F(3) is bonded in a 6-coordinate geometry to two equivalent Cs(1), two equivalent Cs(2), one Fe(1), and one Fe(2) atom.
Cs4Fe3F10 crystallizes in the orthorhombic Cmce space group. There are two inequivalent Cs sites. In the first Cs site, Cs(1) is bonded in a 11-coordinate geometry to one F(2), two equivalent F(4), four equivalent F(1), and four equivalent F(3) atoms. The Cs(1)-F(2) bond length is 3.22 Å. Both Cs(1)-F(4) bond lengths are 3.21 Å. There are a spread of Cs(1)-F(1) bond distances ranging from 3.18-3.53 Å. There are two shorter (3.07 Å) and two longer (3.17 Å) Cs(1)-F(3) bond lengths. In the second Cs site, Cs(2) is bonded in a 10-coordinate geometry to one F(1), two equivalent F(4), three equivalent F(2), and four equivalent F(3) atoms. The Cs(2)-F(1) bond length is 2.92 Å. Both Cs(2)-F(4) bond lengths are 3.14 Å. There is one shorter (3.04 Å) and two longer (3.15 Å) Cs(2)-F(2) bond lengths. There are two shorter (3.05 Å) and two longer (3.10 Å) Cs(2)-F(3) bond lengths. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one F(1), one F(2), two equivalent F(3), and two equivalent F(4) atoms to form a mixture of face and corner-sharing FeF6 octahedra. The corner-sharing octahedral tilt angles are 5°. The Fe(1)-F(1) bond length is 1.92 Å. The Fe(1)-F(2) bond length is 2.10 Å. Both Fe(1)-F(3) bond lengths are 2.17 Å. Both Fe(1)-F(4) bond lengths are 2.09 Å. In the second Fe site, Fe(2) is bonded to two equivalent F(2) and four equivalent F(3) atoms to form face-sharing FeF6 octahedra. Both Fe(2)-F(2) bond lengths are 2.03 Å. All Fe(2)-F(3) bond lengths are 2.00 Å. There are four inequivalent F sites. In the first F site, F(4) is bonded in a distorted linear geometry to two equivalent Cs(1), two equivalent Cs(2), and two equivalent Fe(1) atoms. In the second F site, F(1) is bonded in a distorted single-bond geometry to one Cs(2), four equivalent Cs(1), and one Fe(1) atom. In the third F site, F(2) is bonded in a 2-coordinate geometry to one Cs(1), three equivalent Cs(2), one Fe(1), and one Fe(2) atom. In the fourth F site, F(3) is bonded in a 6-coordinate geometry to two equivalent Cs(1), two equivalent Cs(2), one Fe(1), and one Fe(2) atom.