Yb11Bi10 crystallizes in the tetragonal I4/mmm space group. There are four inequivalent Yb sites. In the first Yb site, Yb(1) is bonded in a 7-coordinate geometry to one Bi(1), two equivalent Bi(3), two equivalent Bi(4), and two equivalent Bi(5) atoms. In the second Yb site, Yb(2) is bonded to one Bi(1), one Bi(2), one Bi(3), and four equivalent Bi(4) atoms to form a mixture of distorted face, corner, and edge-sharing YbBi7 pentagonal bipyramids. In the third Yb site, Yb(3) is bonded in a 9-coordinate geometry to one Bi(2), four equivalent Bi(4), and four equivalent Bi(5) atoms. In the fourth Yb site, Yb(4) is bonded in a 7-coordinate geometry to one Bi(5), two equivalent Bi(2), two equivalent Bi(3), and two equivalent Bi(4) atoms. There are five inequivalent Bi sites. In the first Bi site, Bi(1) is bonded in a 8-coordinate geometry to four equivalent Yb(1) and four equivalent Yb(2) atoms. In the second Bi site, Bi(2) is bonded in a 9-coordinate geometry to one Yb(3), four equivalent Yb(2), and four equivalent Yb(4) atoms. In the third Bi site, Bi(3) is bonded in a 8-coordinate geometry to two equivalent Yb(2), two equivalent Yb(4), and four equivalent Yb(1) atoms. In the fourth Bi site, Bi(4) is bonded in a 10-coordinate geometry to one Yb(3), one Yb(4), two equivalent Yb(1), four equivalent Yb(2), one Bi(4), and one Bi(5) atom. In the fifth Bi site, Bi(5) is bonded in a 11-coordinate geometry to one Yb(4), two equivalent Yb(3), four equivalent Yb(1), two equivalent Bi(4), and two equivalent Bi(5) atoms.
Yb11Bi10 crystallizes in the tetragonal I4/mmm space group. There are four inequivalent Yb sites. In the first Yb site, Yb(1) is bonded in a 7-coordinate geometry to one Bi(1), two equivalent Bi(3), two equivalent Bi(4), and two equivalent Bi(5) atoms. The Yb(1)-Bi(1) bond length is 3.23 Å. Both Yb(1)-Bi(3) bond lengths are 3.23 Å. Both Yb(1)-Bi(4) bond lengths are 3.24 Å. Both Yb(1)-Bi(5) bond lengths are 3.51 Å. In the second Yb site, Yb(2) is bonded to one Bi(1), one Bi(2), one Bi(3), and four equivalent Bi(4) atoms to form a mixture of distorted face, corner, and edge-sharing YbBi7 pentagonal bipyramids. The Yb(2)-Bi(1) bond length is 3.21 Å. The Yb(2)-Bi(2) bond length is 3.25 Å. The Yb(2)-Bi(3) bond length is 3.54 Å. There are two shorter (3.50 Å) and two longer (3.66 Å) Yb(2)-Bi(4) bond lengths. In the third Yb site, Yb(3) is bonded in a 9-coordinate geometry to one Bi(2), four equivalent Bi(4), and four equivalent Bi(5) atoms. The Yb(3)-Bi(2) bond length is 3.66 Å. All Yb(3)-Bi(4) bond lengths are 3.51 Å. All Yb(3)-Bi(5) bond lengths are 3.67 Å. In the fourth Yb site, Yb(4) is bonded in a 7-coordinate geometry to one Bi(5), two equivalent Bi(2), two equivalent Bi(3), and two equivalent Bi(4) atoms. The Yb(4)-Bi(5) bond length is 3.55 Å. Both Yb(4)-Bi(2) bond lengths are 3.57 Å. Both Yb(4)-Bi(3) bond lengths are 2.99 Å. Both Yb(4)-Bi(4) bond lengths are 3.82 Å. There are five inequivalent Bi sites. In the first Bi site, Bi(1) is bonded in a 8-coordinate geometry to four equivalent Yb(1) and four equivalent Yb(2) atoms. In the second Bi site, Bi(2) is bonded in a 9-coordinate geometry to one Yb(3), four equivalent Yb(2), and four equivalent Yb(4) atoms. In the third Bi site, Bi(3) is bonded in a 8-coordinate geometry to two equivalent Yb(2), two equivalent Yb(4), and four equivalent Yb(1) atoms. In the fourth Bi site, Bi(4) is bonded in a 10-coordinate geometry to one Yb(3), one Yb(4), two equivalent Yb(1), four equivalent Yb(2), one Bi(4), and one Bi(5) atom. The Bi(4)-Bi(4) bond length is 3.13 Å. The Bi(4)-Bi(5) bond length is 3.28 Å. In the fifth Bi site, Bi(5) is bonded in a 11-coordinate geometry to one Yb(4), two equivalent Yb(3), four equivalent Yb(1), two equivalent Bi(4), and two equivalent Bi(5) atoms. Both Bi(5)-Bi(5) bond lengths are 3.22 Å.