CsBa2Co2F9 crystallizes in the trigonal R3m space group. Cs(1) is bonded to three equivalent F(1), three equivalent F(3), and six equivalent F(2) atoms to form distorted CsF12 cuboctahedra that share corners with six equivalent Cs(1)F12 cuboctahedra, corners with three equivalent Co(1)F6 octahedra, faces with four equivalent Ba(1)F12 cuboctahedra,  a faceface with one Co(1)F6 octahedra, and faces with three equivalent Co(2)F6 octahedra. The corner-sharing octahedral tilt angles are 26°. There are two inequivalent Ba sites. In the first Ba site, Ba(1) is bonded to three equivalent F(1), three equivalent F(2), and six equivalent F(3) atoms to form BaF12 cuboctahedra that share corners with six equivalent Ba(1)F12 cuboctahedra, faces with four equivalent Cs(1)F12 cuboctahedra, faces with three equivalent Co(1)F6 octahedra, and faces with three equivalent Co(2)F6 octahedra. In the second Ba site, Ba(2) is bonded in a 12-coordinate geometry to three equivalent F(2), three equivalent F(3), and six equivalent F(1) atoms. There are two inequivalent Co sites. In the first Co site, Co(1) is bonded to three equivalent F(1) and three equivalent F(3) atoms to form CoF6 octahedra that share corners with three equivalent Cs(1)F12 cuboctahedra, corners with three equivalent Co(2)F6 octahedra,  a faceface with one Cs(1)F12 cuboctahedra, and faces with three equivalent Ba(1)F12 cuboctahedra. The corner-sharing octahedral tilt angles are 8°. In the second Co site, Co(2) is bonded to three equivalent F(2) and three equivalent F(3) atoms to form CoF6 octahedra that share corners with three equivalent Co(1)F6 octahedra, faces with three equivalent Cs(1)F12 cuboctahedra, and faces with three equivalent Ba(1)F12 cuboctahedra. The corner-sharing octahedral tilt angles are 8°. There are three inequivalent F sites. In the first F site, F(1) is bonded in a distorted single-bond geometry to one Cs(1), one Ba(1), two equivalent Ba(2), and one Co(1) atom. In the second F site, F(2) is bonded in a 5-coordinate geometry to two equivalent Cs(1), one Ba(1), one Ba(2), and one Co(2) atom. In the third F site, F(3) is bonded in a distorted linear geometry to one Cs(1), one Ba(2), two equivalent Ba(1), one Co(1), and one Co(2) atom.
CsBa2Co2F9 crystallizes in the trigonal R3m space group. Cs(1) is bonded to three equivalent F(1), three equivalent F(3), and six equivalent F(2) atoms to form distorted CsF12 cuboctahedra that share corners with six equivalent Cs(1)F12 cuboctahedra, corners with three equivalent Co(1)F6 octahedra, faces with four equivalent Ba(1)F12 cuboctahedra,  a faceface with one Co(1)F6 octahedra, and faces with three equivalent Co(2)F6 octahedra. The corner-sharing octahedral tilt angles are 26°. All Cs(1)-F(1) bond lengths are 2.98 Å. All Cs(1)-F(3) bond lengths are 3.18 Å. All Cs(1)-F(2) bond lengths are 3.02 Å. There are two inequivalent Ba sites. In the first Ba site, Ba(1) is bonded to three equivalent F(1), three equivalent F(2), and six equivalent F(3) atoms to form BaF12 cuboctahedra that share corners with six equivalent Ba(1)F12 cuboctahedra, faces with four equivalent Cs(1)F12 cuboctahedra, faces with three equivalent Co(1)F6 octahedra, and faces with three equivalent Co(2)F6 octahedra. All Ba(1)-F(1) bond lengths are 2.78 Å. All Ba(1)-F(2) bond lengths are 2.79 Å. All Ba(1)-F(3) bond lengths are 3.01 Å. In the second Ba site, Ba(2) is bonded in a 12-coordinate geometry to three equivalent F(2), three equivalent F(3), and six equivalent F(1) atoms. All Ba(2)-F(2) bond lengths are 2.77 Å. All Ba(2)-F(3) bond lengths are 3.13 Å. All Ba(2)-F(1) bond lengths are 3.05 Å. There are two inequivalent Co sites. In the first Co site, Co(1) is bonded to three equivalent F(1) and three equivalent F(3) atoms to form CoF6 octahedra that share corners with three equivalent Cs(1)F12 cuboctahedra, corners with three equivalent Co(2)F6 octahedra,  a faceface with one Cs(1)F12 cuboctahedra, and faces with three equivalent Ba(1)F12 cuboctahedra. The corner-sharing octahedral tilt angles are 8°. All Co(1)-F(1) bond lengths are 2.00 Å. All Co(1)-F(3) bond lengths are 2.14 Å. In the second Co site, Co(2) is bonded to three equivalent F(2) and three equivalent F(3) atoms to form CoF6 octahedra that share corners with three equivalent Co(1)F6 octahedra, faces with three equivalent Cs(1)F12 cuboctahedra, and faces with three equivalent Ba(1)F12 cuboctahedra. The corner-sharing octahedral tilt angles are 8°. All Co(2)-F(2) bond lengths are 2.02 Å. All Co(2)-F(3) bond lengths are 2.15 Å. There are three inequivalent F sites. In the first F site, F(1) is bonded in a distorted single-bond geometry to one Cs(1), one Ba(1), two equivalent Ba(2), and one Co(1) atom. In the second F site, F(2) is bonded in a 5-coordinate geometry to two equivalent Cs(1), one Ba(1), one Ba(2), and one Co(2) atom. In the third F site, F(3) is bonded in a distorted linear geometry to one Cs(1), one Ba(2), two equivalent Ba(1), one Co(1), and one Co(2) atom.