RbTiBr3 crystallizes in the monoclinic C2/m space group. Rb(1) is bonded to four equivalent Br(2) and eight equivalent Br(1) atoms to form RbBr12 cuboctahedra that share corners with six equivalent Rb(1)Br12 cuboctahedra, corners with three equivalent Ti(1)Br6 octahedra, corners with three equivalent Ti(2)Br6 octahedra, faces with eight equivalent Rb(1)Br12 cuboctahedra, faces with three equivalent Ti(1)Br6 octahedra, and faces with three equivalent Ti(2)Br6 octahedra. The corner-sharing octahedral tilt angles range from 18-20°. There are two inequivalent Ti sites. In the first Ti site, Ti(1) is bonded to two equivalent Br(2) and four equivalent Br(1) atoms to form TiBr6 octahedra that share corners with six equivalent Rb(1)Br12 cuboctahedra, faces with six equivalent Rb(1)Br12 cuboctahedra, and faces with two equivalent Ti(2)Br6 octahedra. In the second Ti site, Ti(2) is bonded to two equivalent Br(2) and four equivalent Br(1) atoms to form TiBr6 octahedra that share corners with six equivalent Rb(1)Br12 cuboctahedra, faces with six equivalent Rb(1)Br12 cuboctahedra, and faces with two equivalent Ti(1)Br6 octahedra. There are two inequivalent Br sites. In the first Br site, Br(1) is bonded in a 6-coordinate geometry to four equivalent Rb(1), one Ti(1), and one Ti(2) atom. In the second Br site, Br(2) is bonded to four equivalent Rb(1), one Ti(1), and one Ti(2) atom to form a mixture of distorted corner and edge-sharing BrRb4Ti2 octahedra. The corner-sharing octahedral tilt angles range from 0-68°.
RbTiBr3 crystallizes in the monoclinic C2/m space group. Rb(1) is bonded to four equivalent Br(2) and eight equivalent Br(1) atoms to form RbBr12 cuboctahedra that share corners with six equivalent Rb(1)Br12 cuboctahedra, corners with three equivalent Ti(1)Br6 octahedra, corners with three equivalent Ti(2)Br6 octahedra, faces with eight equivalent Rb(1)Br12 cuboctahedra, faces with three equivalent Ti(1)Br6 octahedra, and faces with three equivalent Ti(2)Br6 octahedra. The corner-sharing octahedral tilt angles range from 18-20°. There are a spread of Rb(1)-Br(2) bond distances ranging from 3.75-3.92 Å. There are a spread of Rb(1)-Br(1) bond distances ranging from 3.75-3.92 Å. There are two inequivalent Ti sites. In the first Ti site, Ti(1) is bonded to two equivalent Br(2) and four equivalent Br(1) atoms to form TiBr6 octahedra that share corners with six equivalent Rb(1)Br12 cuboctahedra, faces with six equivalent Rb(1)Br12 cuboctahedra, and faces with two equivalent Ti(2)Br6 octahedra. Both Ti(1)-Br(2) bond lengths are 2.69 Å. All Ti(1)-Br(1) bond lengths are 2.67 Å. In the second Ti site, Ti(2) is bonded to two equivalent Br(2) and four equivalent Br(1) atoms to form TiBr6 octahedra that share corners with six equivalent Rb(1)Br12 cuboctahedra, faces with six equivalent Rb(1)Br12 cuboctahedra, and faces with two equivalent Ti(1)Br6 octahedra. Both Ti(2)-Br(2) bond lengths are 2.70 Å. All Ti(2)-Br(1) bond lengths are 2.70 Å. There are two inequivalent Br sites. In the first Br site, Br(1) is bonded in a 6-coordinate geometry to four equivalent Rb(1), one Ti(1), and one Ti(2) atom. In the second Br site, Br(2) is bonded to four equivalent Rb(1), one Ti(1), and one Ti(2) atom to form a mixture of distorted corner and edge-sharing BrRb4Ti2 octahedra. The corner-sharing octahedral tilt angles range from 0-68°.