Rb3Yb7Se12 is Krennerite-derived structured and crystallizes in the orthorhombic Pmn2_1 space group. There are three inequivalent Rb sites. In the first Rb site, Rb(1) is bonded in a 6-coordinate geometry to one Se(4), one Se(9), two equivalent Se(6), and two equivalent Se(8) atoms. In the second Rb site, Rb(2) is bonded in a 4-coordinate geometry to two equivalent Se(5) and two equivalent Se(7) atoms. In the third Rb site, Rb(3) is bonded to one Se(7), one Se(8), two equivalent Se(1), and two equivalent Se(2) atoms to form distorted RbSe6 octahedra that share edges with two equivalent Rb(3)Se6 octahedra, edges with two equivalent Yb(6)Se6 octahedra, and edges with two equivalent Yb(7)Se6 octahedra. There are seven inequivalent Yb sites. In the first Yb site, Yb(1) is bonded in a 4-coordinate geometry to one Se(3), one Se(5), two equivalent Se(1), and two equivalent Se(9) atoms. In the second Yb site, Yb(2) is bonded in a 4-coordinate geometry to one Se(11), one Se(4), one Se(6), two equivalent Se(10), and two equivalent Se(2) atoms. In the third Yb site, Yb(3) is bonded in a 6-coordinate geometry to one Se(7), one Se(9), two equivalent Se(12), and two equivalent Se(3) atoms. In the fourth Yb site, Yb(4) is bonded in a 4-coordinate geometry to one Se(10), one Se(8), two equivalent Se(11), and two equivalent Se(4) atoms. In the fifth Yb site, Yb(5) is bonded to one Se(10), one Se(9), two equivalent Se(5), and two equivalent Se(6) atoms to form edge-sharing YbSe6 octahedra. In the sixth Yb site, Yb(6) is bonded to one Se(1), one Se(11), two equivalent Se(3), and two equivalent Se(8) atoms to form distorted YbSe6 octahedra that share edges with two equivalent Rb(3)Se6 octahedra and edges with two equivalent Yb(6)Se6 octahedra. In the seventh Yb site, Yb(7) is bonded to one Se(12), one Se(2), two equivalent Se(4), and two equivalent Se(7) atoms to form YbSe6 octahedra that share edges with two equivalent Rb(3)Se6 octahedra and edges with two equivalent Yb(7)Se6 octahedra. There are twelve inequivalent Se sites. In the first Se site, Se(1) is bonded in a 5-coordinate geometry to two equivalent Rb(3), one Yb(6), and two equivalent Yb(1) atoms. In the second Se site, Se(2) is bonded to two equivalent Rb(3), one Yb(7), and two equivalent Yb(2) atoms to form SeRb2Yb3 square pyramids that share corners with two equivalent Se(8)Rb3Yb3 octahedra, edges with two equivalent Se(7)Rb3Yb3 octahedra, edges with two equivalent Se(4)RbYb5 octahedra, and edges with two equivalent Se(2)Rb2Yb3 square pyramids. The corner-sharing octahedral tilt angles are 72°. In the third Se site, Se(3) is bonded to one Yb(1), two equivalent Yb(3), and two equivalent Yb(6) atoms to form SeYb5 square pyramids that share corners with two equivalent Se(7)Rb3Yb3 octahedra, corners with two equivalent Se(8)Rb3Yb3 octahedra,  an edgeedge with one Se(8)Rb3Yb3 octahedra, and edges with two equivalent Se(3)Yb5 square pyramids. The corner-sharing octahedral tilt angles range from 11-65°. In the fourth Se site, Se(4) is bonded to one Rb(1), one Yb(2), two equivalent Yb(4), and two equivalent Yb(7) atoms to form distorted SeRbYb5 octahedra that share corners with two equivalent Se(7)Rb3Yb3 octahedra,  an edgeedge with one Se(7)Rb3Yb3 octahedra, edges with two equivalent Se(8)Rb3Yb3 octahedra, edges with two equivalent Se(4)RbYb5 octahedra, and edges with two equivalent Se(2)Rb2Yb3 square pyramids. The corner-sharing octahedral tilt angles are 10°. In the fifth Se site, Se(5) is bonded in a 5-coordinate geometry to two equivalent Rb(2), one Yb(1), and two equivalent Yb(5) atoms. In the sixth Se site, Se(6) is bonded in a 5-coordinate geometry to two equivalent Rb(1), one Yb(2), and two equivalent Yb(5) atoms. In the seventh Se site, Se(7) is bonded to one Rb(3), two equivalent Rb(2), one Yb(3), and two equivalent Yb(7) atoms to form distorted SeRb3Yb3 octahedra that share  a cornercorner with one Se(8)Rb3Yb3 octahedra, corners with two equivalent Se(4)RbYb5 octahedra, corners with two equivalent Se(3)Yb5 square pyramids,  an edgeedge with one Se(4)RbYb5 octahedra, edges with two equivalent Se(7)Rb3Yb3 octahedra, and edges with two equivalent Se(2)Rb2Yb3 square pyramids. The corner-sharing octahedral tilt angles range from 3-10°. In the eighth Se site, Se(8) is bonded to one Rb(3), two equivalent Rb(1), one Yb(4), and two equivalent Yb(6) atoms to form distorted SeRb3Yb3 octahedra that share  a cornercorner with one Se(7)Rb3Yb3 octahedra, corners with two equivalent Se(2)Rb2Yb3 square pyramids, corners with two equivalent Se(3)Yb5 square pyramids, edges with two equivalent Se(8)Rb3Yb3 octahedra, edges with two equivalent Se(4)RbYb5 octahedra, and  an edgeedge with one Se(3)Yb5 square pyramid. The corner-sharing octahedral tilt angles are 3°. In the ninth Se site, Se(9) is bonded in a 7-coordinate geometry to one Rb(1), one Yb(3), one Yb(5), two equivalent Yb(1), and two equivalent Se(12) atoms. In the tenth Se site, Se(10) is bonded in a 6-coordinate geometry to one Yb(4), one Yb(5), two equivalent Yb(2), and two equivalent Se(11) atoms. In the eleventh Se site, Se(11) is bonded in a 6-coordinate geometry to one Yb(2), one Yb(6), two equivalent Yb(4), and two equivalent Se(10) atoms. In the twelfth Se site, Se(12) is bonded in a 5-coordinate geometry to one Yb(7), two equivalent Yb(3), and two equivalent Se(9) atoms.
Rb3Yb7Se12 is Krennerite-derived structured and crystallizes in the orthorhombic Pmn2_1 space group. There are three inequivalent Rb sites. In the first Rb site, Rb(1) is bonded in a 6-coordinate geometry to one Se(4), one Se(9), two equivalent Se(6), and two equivalent Se(8) atoms. The Rb(1)-Se(4) bond length is 3.78 Å. The Rb(1)-Se(9) bond length is 3.97 Å. Both Rb(1)-Se(6) bond lengths are 3.54 Å. Both Rb(1)-Se(8) bond lengths are 3.51 Å. In the second Rb site, Rb(2) is bonded in a 4-coordinate geometry to two equivalent Se(5) and two equivalent Se(7) atoms. Both Rb(2)-Se(5) bond lengths are 3.60 Å. Both Rb(2)-Se(7) bond lengths are 3.52 Å. In the third Rb site, Rb(3) is bonded to one Se(7), one Se(8), two equivalent Se(1), and two equivalent Se(2) atoms to form distorted RbSe6 octahedra that share edges with two equivalent Rb(3)Se6 octahedra, edges with two equivalent Yb(6)Se6 octahedra, and edges with two equivalent Yb(7)Se6 octahedra. The Rb(3)-Se(7) bond length is 3.90 Å. The Rb(3)-Se(8) bond length is 3.66 Å. Both Rb(3)-Se(1) bond lengths are 3.43 Å. Both Rb(3)-Se(2) bond lengths are 3.41 Å. There are seven inequivalent Yb sites. In the first Yb site, Yb(1) is bonded in a 4-coordinate geometry to one Se(3), one Se(5), two equivalent Se(1), and two equivalent Se(9) atoms. The Yb(1)-Se(3) bond length is 2.96 Å. The Yb(1)-Se(5) bond length is 2.84 Å. Both Yb(1)-Se(1) bond lengths are 2.81 Å. Both Yb(1)-Se(9) bond lengths are 3.49 Å. In the second Yb site, Yb(2) is bonded in a 4-coordinate geometry to one Se(11), one Se(4), one Se(6), two equivalent Se(10), and two equivalent Se(2) atoms. The Yb(2)-Se(11) bond length is 3.71 Å. The Yb(2)-Se(4) bond length is 2.97 Å. The Yb(2)-Se(6) bond length is 2.85 Å. Both Yb(2)-Se(10) bond lengths are 3.47 Å. Both Yb(2)-Se(2) bond lengths are 2.80 Å. In the third Yb site, Yb(3) is bonded in a 6-coordinate geometry to one Se(7), one Se(9), two equivalent Se(12), and two equivalent Se(3) atoms. The Yb(3)-Se(7) bond length is 2.78 Å. The Yb(3)-Se(9) bond length is 2.92 Å. Both Yb(3)-Se(12) bond lengths are 3.41 Å. Both Yb(3)-Se(3) bond lengths are 2.88 Å. In the fourth Yb site, Yb(4) is bonded in a 4-coordinate geometry to one Se(10), one Se(8), two equivalent Se(11), and two equivalent Se(4) atoms. The Yb(4)-Se(10) bond length is 2.92 Å. The Yb(4)-Se(8) bond length is 2.77 Å. Both Yb(4)-Se(11) bond lengths are 3.47 Å. Both Yb(4)-Se(4) bond lengths are 2.88 Å. In the fifth Yb site, Yb(5) is bonded to one Se(10), one Se(9), two equivalent Se(5), and two equivalent Se(6) atoms to form edge-sharing YbSe6 octahedra. The Yb(5)-Se(10) bond length is 3.06 Å. The Yb(5)-Se(9) bond length is 3.05 Å. Both Yb(5)-Se(5) bond lengths are 2.82 Å. Both Yb(5)-Se(6) bond lengths are 2.83 Å. In the sixth Yb site, Yb(6) is bonded to one Se(1), one Se(11), two equivalent Se(3), and two equivalent Se(8) atoms to form distorted YbSe6 octahedra that share edges with two equivalent Rb(3)Se6 octahedra and edges with two equivalent Yb(6)Se6 octahedra. The Yb(6)-Se(1) bond length is 2.88 Å. The Yb(6)-Se(11) bond length is 3.52 Å. Both Yb(6)-Se(3) bond lengths are 3.12 Å. Both Yb(6)-Se(8) bond lengths are 2.92 Å. In the seventh Yb site, Yb(7) is bonded to one Se(12), one Se(2), two equivalent Se(4), and two equivalent Se(7) atoms to form YbSe6 octahedra that share edges with two equivalent Rb(3)Se6 octahedra and edges with two equivalent Yb(7)Se6 octahedra. The Yb(7)-Se(12) bond length is 3.44 Å. The Yb(7)-Se(2) bond length is 2.86 Å. Both Yb(7)-Se(4) bond lengths are 3.14 Å. Both Yb(7)-Se(7) bond lengths are 2.92 Å. There are twelve inequivalent Se sites. In the first Se site, Se(1) is bonded in a 5-coordinate geometry to two equivalent Rb(3), one Yb(6), and two equivalent Yb(1) atoms. In the second Se site, Se(2) is bonded to two equivalent Rb(3), one Yb(7), and two equivalent Yb(2) atoms to form SeRb2Yb3 square pyramids that share corners with two equivalent Se(8)Rb3Yb3 octahedra, edges with two equivalent Se(7)Rb3Yb3 octahedra, edges with two equivalent Se(4)RbYb5 octahedra, and edges with two equivalent Se(2)Rb2Yb3 square pyramids. The corner-sharing octahedral tilt angles are 72°. In the third Se site, Se(3) is bonded to one Yb(1), two equivalent Yb(3), and two equivalent Yb(6) atoms to form SeYb5 square pyramids that share corners with two equivalent Se(7)Rb3Yb3 octahedra, corners with two equivalent Se(8)Rb3Yb3 octahedra,  an edgeedge with one Se(8)Rb3Yb3 octahedra, and edges with two equivalent Se(3)Yb5 square pyramids. The corner-sharing octahedral tilt angles range from 11-65°. In the fourth Se site, Se(4) is bonded to one Rb(1), one Yb(2), two equivalent Yb(4), and two equivalent Yb(7) atoms to form distorted SeRbYb5 octahedra that share corners with two equivalent Se(7)Rb3Yb3 octahedra,  an edgeedge with one Se(7)Rb3Yb3 octahedra, edges with two equivalent Se(8)Rb3Yb3 octahedra, edges with two equivalent Se(4)RbYb5 octahedra, and edges with two equivalent Se(2)Rb2Yb3 square pyramids. The corner-sharing octahedral tilt angles are 10°. In the fifth Se site, Se(5) is bonded in a 5-coordinate geometry to two equivalent Rb(2), one Yb(1), and two equivalent Yb(5) atoms. In the sixth Se site, Se(6) is bonded in a 5-coordinate geometry to two equivalent Rb(1), one Yb(2), and two equivalent Yb(5) atoms. In the seventh Se site, Se(7) is bonded to one Rb(3), two equivalent Rb(2), one Yb(3), and two equivalent Yb(7) atoms to form distorted SeRb3Yb3 octahedra that share  a cornercorner with one Se(8)Rb3Yb3 octahedra, corners with two equivalent Se(4)RbYb5 octahedra, corners with two equivalent Se(3)Yb5 square pyramids,  an edgeedge with one Se(4)RbYb5 octahedra, edges with two equivalent Se(7)Rb3Yb3 octahedra, and edges with two equivalent Se(2)Rb2Yb3 square pyramids. The corner-sharing octahedral tilt angles range from 3-10°. In the eighth Se site, Se(8) is bonded to one Rb(3), two equivalent Rb(1), one Yb(4), and two equivalent Yb(6) atoms to form distorted SeRb3Yb3 octahedra that share  a cornercorner with one Se(7)Rb3Yb3 octahedra, corners with two equivalent Se(2)Rb2Yb3 square pyramids, corners with two equivalent Se(3)Yb5 square pyramids, edges with two equivalent Se(8)Rb3Yb3 octahedra, edges with two equivalent Se(4)RbYb5 octahedra, and  an edgeedge with one Se(3)Yb5 square pyramid. The corner-sharing octahedral tilt angles are 3°. In the ninth Se site, Se(9) is bonded in a 7-coordinate geometry to one Rb(1), one Yb(3), one Yb(5), two equivalent Yb(1), and two equivalent Se(12) atoms. Both Se(9)-Se(12) bond lengths are 2.53 Å. In the tenth Se site, Se(10) is bonded in a 6-coordinate geometry to one Yb(4), one Yb(5), two equivalent Yb(2), and two equivalent Se(11) atoms. Both Se(10)-Se(11) bond lengths are 2.52 Å. In the eleventh Se site, Se(11) is bonded in a 6-coordinate geometry to one Yb(2), one Yb(6), two equivalent Yb(4), and two equivalent Se(10) atoms. In the twelfth Se site, Se(12) is bonded in a 5-coordinate geometry to one Yb(7), two equivalent Yb(3), and two equivalent Se(9) atoms.