Rb3(Cu4Se3)2 crystallizes in the monoclinic C2/m space group. There are two inequivalent Rb sites. In the first Rb site, Rb(1) is bonded in a 7-coordinate geometry to two equivalent Se(1), two equivalent Se(2), and three equivalent Se(3) atoms. In the second Rb site, Rb(2) is bonded in a body-centered cubic geometry to four equivalent Se(1) and four equivalent Se(2) atoms. There are four inequivalent Cu sites. In the first Cu site, Cu(1) is bonded in a 3-coordinate geometry to one Se(2) and two equivalent Se(3) atoms. In the second Cu site, Cu(2) is bonded to one Se(3) and three equivalent Se(1) atoms to form a mixture of distorted edge and corner-sharing CuSe4 tetrahedra. In the third Cu site, Cu(3) is bonded in a distorted trigonal planar geometry to one Se(3) and two equivalent Se(2) atoms. In the fourth Cu site, Cu(4) is bonded in a 4-coordinate geometry to one Se(1), one Se(2), and two equivalent Se(3) atoms. There are three inequivalent Se sites. In the first Se site, Se(1) is bonded in a 8-coordinate geometry to two equivalent Rb(1), two equivalent Rb(2), one Cu(4), and three equivalent Cu(2) atoms. In the second Se site, Se(2) is bonded in a 8-coordinate geometry to two equivalent Rb(1), two equivalent Rb(2), one Cu(1), one Cu(4), and two equivalent Cu(3) atoms. In the third Se site, Se(3) is bonded in a 9-coordinate geometry to three equivalent Rb(1), one Cu(2), one Cu(3), two equivalent Cu(1), and two equivalent Cu(4) atoms.
Rb3(Cu4Se3)2 crystallizes in the monoclinic C2/m space group. There are two inequivalent Rb sites. In the first Rb site, Rb(1) is bonded in a 7-coordinate geometry to two equivalent Se(1), two equivalent Se(2), and three equivalent Se(3) atoms. Both Rb(1)-Se(1) bond lengths are 3.43 Å. Both Rb(1)-Se(2) bond lengths are 3.46 Å. There are two shorter (3.43 Å) and one longer (3.79 Å) Rb(1)-Se(3) bond length. In the second Rb site, Rb(2) is bonded in a body-centered cubic geometry to four equivalent Se(1) and four equivalent Se(2) atoms. All Rb(2)-Se(1) bond lengths are 3.54 Å. All Rb(2)-Se(2) bond lengths are 3.48 Å. There are four inequivalent Cu sites. In the first Cu site, Cu(1) is bonded in a 3-coordinate geometry to one Se(2) and two equivalent Se(3) atoms. The Cu(1)-Se(2) bond length is 2.35 Å. Both Cu(1)-Se(3) bond lengths are 2.54 Å. In the second Cu site, Cu(2) is bonded to one Se(3) and three equivalent Se(1) atoms to form a mixture of distorted edge and corner-sharing CuSe4 tetrahedra. The Cu(2)-Se(3) bond length is 2.58 Å. There are two shorter (2.47 Å) and one longer (2.48 Å) Cu(2)-Se(1) bond length. In the third Cu site, Cu(3) is bonded in a distorted trigonal planar geometry to one Se(3) and two equivalent Se(2) atoms. The Cu(3)-Se(3) bond length is 2.45 Å. Both Cu(3)-Se(2) bond lengths are 2.44 Å. In the fourth Cu site, Cu(4) is bonded in a 4-coordinate geometry to one Se(1), one Se(2), and two equivalent Se(3) atoms. The Cu(4)-Se(1) bond length is 2.36 Å. The Cu(4)-Se(2) bond length is 2.49 Å. Both Cu(4)-Se(3) bond lengths are 2.69 Å. There are three inequivalent Se sites. In the first Se site, Se(1) is bonded in a 8-coordinate geometry to two equivalent Rb(1), two equivalent Rb(2), one Cu(4), and three equivalent Cu(2) atoms. In the second Se site, Se(2) is bonded in a 8-coordinate geometry to two equivalent Rb(1), two equivalent Rb(2), one Cu(1), one Cu(4), and two equivalent Cu(3) atoms. In the third Se site, Se(3) is bonded in a 9-coordinate geometry to three equivalent Rb(1), one Cu(2), one Cu(3), two equivalent Cu(1), and two equivalent Cu(4) atoms.