Rb2CoBr4 crystallizes in the orthorhombic Pnma space group. There are two inequivalent Rb sites. In the first Rb site, Rb(1) is bonded in a 8-coordinate geometry to one Br(2), three equivalent Br(3), and four equivalent Br(1) atoms. In the second Rb site, Rb(2) is bonded in a 9-coordinate geometry to two equivalent Br(3), three equivalent Br(2), and four equivalent Br(1) atoms. Co(1) is bonded in a tetrahedral geometry to one Br(2), one Br(3), and two equivalent Br(1) atoms. There are three inequivalent Br sites. In the first Br site, Br(1) is bonded to two equivalent Rb(1), two equivalent Rb(2), and one Co(1) atom to form a mixture of distorted edge, corner, and face-sharing BrRb4Co square pyramids. In the second Br site, Br(2) is bonded in a 5-coordinate geometry to one Rb(1), three equivalent Rb(2), and one Co(1) atom. In the third Br site, Br(3) is bonded in a 6-coordinate geometry to two equivalent Rb(2), three equivalent Rb(1), and one Co(1) atom.
Rb2CoBr4 crystallizes in the orthorhombic Pnma space group. There are two inequivalent Rb sites. In the first Rb site, Rb(1) is bonded in a 8-coordinate geometry to one Br(2), three equivalent Br(3), and four equivalent Br(1) atoms. The Rb(1)-Br(2) bond length is 3.50 Å. There is one shorter (3.81 Å) and two longer (3.84 Å) Rb(1)-Br(3) bond lengths. There are two shorter (3.66 Å) and two longer (3.71 Å) Rb(1)-Br(1) bond lengths. In the second Rb site, Rb(2) is bonded in a 9-coordinate geometry to two equivalent Br(3), three equivalent Br(2), and four equivalent Br(1) atoms. There is one shorter (3.43 Å) and one longer (3.55 Å) Rb(2)-Br(3) bond length. There is one shorter (3.51 Å) and two longer (3.97 Å) Rb(2)-Br(2) bond lengths. There are two shorter (3.51 Å) and two longer (3.53 Å) Rb(2)-Br(1) bond lengths. Co(1) is bonded in a tetrahedral geometry to one Br(2), one Br(3), and two equivalent Br(1) atoms. The Co(1)-Br(2) bond length is 2.39 Å. The Co(1)-Br(3) bond length is 2.40 Å. Both Co(1)-Br(1) bond lengths are 2.39 Å. There are three inequivalent Br sites. In the first Br site, Br(1) is bonded to two equivalent Rb(1), two equivalent Rb(2), and one Co(1) atom to form a mixture of distorted edge, corner, and face-sharing BrRb4Co square pyramids. In the second Br site, Br(2) is bonded in a 5-coordinate geometry to one Rb(1), three equivalent Rb(2), and one Co(1) atom. In the third Br site, Br(3) is bonded in a 6-coordinate geometry to two equivalent Rb(2), three equivalent Rb(1), and one Co(1) atom.