Yb9Mn4Bi9 is Magnesium tetraboride-derived structured and crystallizes in the orthorhombic Pbam space group. There are five inequivalent Yb sites. In the first Yb site, Yb(1) is bonded in a 8-coordinate geometry to two equivalent Mn(1), two equivalent Bi(4), and four equivalent Bi(2) atoms. In the second Yb site, Yb(2) is bonded in a 10-coordinate geometry to two equivalent Mn(1), two equivalent Mn(2), one Bi(2), one Bi(3), two equivalent Bi(4), and two equivalent Bi(5) atoms. In the third Yb site, Yb(3) is bonded in a 8-coordinate geometry to two equivalent Mn(1), one Bi(2), one Bi(3), two equivalent Bi(1), and two equivalent Bi(5) atoms. In the fourth Yb site, Yb(4) is bonded to two equivalent Bi(3), two equivalent Bi(4), and two equivalent Bi(5) atoms to form a mixture of distorted edge and corner-sharing YbBi6 octahedra. The corner-sharing octahedral tilt angles are 45°. In the fifth Yb site, Yb(5) is bonded in a 7-coordinate geometry to one Mn(1), one Bi(1), one Bi(4), two equivalent Bi(2), and two equivalent Bi(3) atoms. There are two inequivalent Mn sites. In the first Mn site, Mn(1) is bonded in a 10-coordinate geometry to one Yb(1), one Yb(5), two equivalent Yb(2), two equivalent Yb(3), one Bi(1), one Bi(5), and two equivalent Bi(2) atoms. In the second Mn site, Mn(2) is bonded in a 4-coordinate geometry to two equivalent Yb(2), one Bi(4), one Bi(5), and two equivalent Bi(3) atoms. There are five inequivalent Bi sites. In the first Bi site, Bi(3) is bonded in a 7-coordinate geometry to one Yb(2), one Yb(3), two equivalent Yb(4), two equivalent Yb(5), and two equivalent Mn(2) atoms. In the second Bi site, Bi(4) is bonded in a 7-coordinate geometry to one Yb(1), one Yb(5), two equivalent Yb(2), two equivalent Yb(4), and one Mn(2) atom. In the third Bi site, Bi(5) is bonded in a 8-coordinate geometry to two equivalent Yb(2), two equivalent Yb(3), two equivalent Yb(4), one Mn(1), and one Mn(2) atom. In the fourth Bi site, Bi(1) is bonded in a body-centered cubic geometry to two equivalent Yb(5), four equivalent Yb(3), and two equivalent Mn(1) atoms. In the fifth Bi site, Bi(2) is bonded in a 8-coordinate geometry to one Yb(2), one Yb(3), two equivalent Yb(1), two equivalent Yb(5), and two equivalent Mn(1) atoms.
Yb9Mn4Bi9 is Magnesium tetraboride-derived structured and crystallizes in the orthorhombic Pbam space group. There are five inequivalent Yb sites. In the first Yb site, Yb(1) is bonded in a 8-coordinate geometry to two equivalent Mn(1), two equivalent Bi(4), and four equivalent Bi(2) atoms. Both Yb(1)-Mn(1) bond lengths are 3.57 Å. Both Yb(1)-Bi(4) bond lengths are 3.31 Å. All Yb(1)-Bi(2) bond lengths are 3.39 Å. In the second Yb site, Yb(2) is bonded in a 10-coordinate geometry to two equivalent Mn(1), two equivalent Mn(2), one Bi(2), one Bi(3), two equivalent Bi(4), and two equivalent Bi(5) atoms. Both Yb(2)-Mn(1) bond lengths are 3.59 Å. Both Yb(2)-Mn(2) bond lengths are 3.30 Å. The Yb(2)-Bi(2) bond length is 3.30 Å. The Yb(2)-Bi(3) bond length is 3.75 Å. Both Yb(2)-Bi(4) bond lengths are 3.23 Å. Both Yb(2)-Bi(5) bond lengths are 3.32 Å. In the third Yb site, Yb(3) is bonded in a 8-coordinate geometry to two equivalent Mn(1), one Bi(2), one Bi(3), two equivalent Bi(1), and two equivalent Bi(5) atoms. Both Yb(3)-Mn(1) bond lengths are 3.24 Å. The Yb(3)-Bi(2) bond length is 3.66 Å. The Yb(3)-Bi(3) bond length is 3.26 Å. Both Yb(3)-Bi(1) bond lengths are 3.22 Å. Both Yb(3)-Bi(5) bond lengths are 3.33 Å. In the fourth Yb site, Yb(4) is bonded to two equivalent Bi(3), two equivalent Bi(4), and two equivalent Bi(5) atoms to form a mixture of distorted edge and corner-sharing YbBi6 octahedra. The corner-sharing octahedral tilt angles are 45°. There is one shorter (3.32 Å) and one longer (3.42 Å) Yb(4)-Bi(3) bond length. Both Yb(4)-Bi(4) bond lengths are 3.24 Å. Both Yb(4)-Bi(5) bond lengths are 3.27 Å. In the fifth Yb site, Yb(5) is bonded in a 7-coordinate geometry to one Mn(1), one Bi(1), one Bi(4), two equivalent Bi(2), and two equivalent Bi(3) atoms. The Yb(5)-Mn(1) bond length is 3.28 Å. The Yb(5)-Bi(1) bond length is 3.48 Å. The Yb(5)-Bi(4) bond length is 3.23 Å. Both Yb(5)-Bi(2) bond lengths are 3.38 Å. Both Yb(5)-Bi(3) bond lengths are 3.32 Å. There are two inequivalent Mn sites. In the first Mn site, Mn(1) is bonded in a 10-coordinate geometry to one Yb(1), one Yb(5), two equivalent Yb(2), two equivalent Yb(3), one Bi(1), one Bi(5), and two equivalent Bi(2) atoms. The Mn(1)-Bi(1) bond length is 2.96 Å. The Mn(1)-Bi(5) bond length is 2.80 Å. Both Mn(1)-Bi(2) bond lengths are 2.83 Å. In the second Mn site, Mn(2) is bonded in a 4-coordinate geometry to two equivalent Yb(2), one Bi(4), one Bi(5), and two equivalent Bi(3) atoms. The Mn(2)-Bi(4) bond length is 2.82 Å. The Mn(2)-Bi(5) bond length is 2.95 Å. Both Mn(2)-Bi(3) bond lengths are 2.81 Å. There are five inequivalent Bi sites. In the first Bi site, Bi(3) is bonded in a 7-coordinate geometry to one Yb(2), one Yb(3), two equivalent Yb(4), two equivalent Yb(5), and two equivalent Mn(2) atoms. In the second Bi site, Bi(4) is bonded in a 7-coordinate geometry to one Yb(1), one Yb(5), two equivalent Yb(2), two equivalent Yb(4), and one Mn(2) atom. In the third Bi site, Bi(5) is bonded in a 8-coordinate geometry to two equivalent Yb(2), two equivalent Yb(3), two equivalent Yb(4), one Mn(1), and one Mn(2) atom. In the fourth Bi site, Bi(1) is bonded in a body-centered cubic geometry to two equivalent Yb(5), four equivalent Yb(3), and two equivalent Mn(1) atoms. In the fifth Bi site, Bi(2) is bonded in a 8-coordinate geometry to one Yb(2), one Yb(3), two equivalent Yb(1), two equivalent Yb(5), and two equivalent Mn(1) atoms.