Ca9Zn4Bi9 crystallizes in the orthorhombic Pbam space group. There are five inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 6-coordinate geometry to two equivalent Zn(1), two equivalent Bi(4), and four equivalent Bi(5) atoms. In the second Ca site, Ca(2) is bonded to two equivalent Bi(2), two equivalent Bi(3), and two equivalent Bi(4) atoms to form a mixture of edge and corner-sharing CaBi6 octahedra. The corner-sharing octahedral tilt angles are 43°. In the third Ca site, Ca(3) is bonded in a 7-coordinate geometry to one Zn(1), one Bi(1), one Bi(4), two equivalent Bi(2), and two equivalent Bi(5) atoms. In the fourth Ca site, Ca(4) is bonded in a 7-coordinate geometry to two equivalent Zn(1), one Bi(2), two equivalent Bi(1), and two equivalent Bi(3) atoms. In the fifth Ca site, Ca(5) is bonded in a 7-coordinate geometry to two equivalent Zn(1), two equivalent Zn(2), one Bi(5), two equivalent Bi(3), and two equivalent Bi(4) atoms. There are two inequivalent Zn sites. In the first Zn site, Zn(1) is bonded in a 10-coordinate geometry to one Ca(1), one Ca(3), two equivalent Ca(4), two equivalent Ca(5), one Bi(1), one Bi(3), and two equivalent Bi(5) atoms. In the second Zn site, Zn(2) is bonded in a 6-coordinate geometry to two equivalent Ca(5), one Bi(3), one Bi(4), and two equivalent Bi(2) atoms. There are five inequivalent Bi sites. In the first Bi site, Bi(3) is bonded in a 8-coordinate geometry to two equivalent Ca(2), two equivalent Ca(4), two equivalent Ca(5), one Zn(1), and one Zn(2) atom. In the second Bi site, Bi(4) is bonded to one Ca(1), one Ca(3), two equivalent Ca(2), two equivalent Ca(5), and one Zn(2) atom to form a mixture of distorted edge and corner-sharing BiCa6Zn pentagonal bipyramids. In the third Bi site, Bi(5) is bonded in a 7-coordinate geometry to one Ca(5), two equivalent Ca(1), two equivalent Ca(3), and two equivalent Zn(1) atoms. In the fourth Bi site, Bi(1) is bonded in a distorted body-centered cubic geometry to two equivalent Ca(3), four equivalent Ca(4), and two equivalent Zn(1) atoms. In the fifth Bi site, Bi(2) is bonded in a 7-coordinate geometry to one Ca(4), two equivalent Ca(2), two equivalent Ca(3), and two equivalent Zn(2) atoms.
Ca9Zn4Bi9 crystallizes in the orthorhombic Pbam space group. There are five inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 6-coordinate geometry to two equivalent Zn(1), two equivalent Bi(4), and four equivalent Bi(5) atoms. Both Ca(1)-Zn(1) bond lengths are 3.61 Å. Both Ca(1)-Bi(4) bond lengths are 3.27 Å. All Ca(1)-Bi(5) bond lengths are 3.37 Å. In the second Ca site, Ca(2) is bonded to two equivalent Bi(2), two equivalent Bi(3), and two equivalent Bi(4) atoms to form a mixture of edge and corner-sharing CaBi6 octahedra. The corner-sharing octahedral tilt angles are 43°. There is one shorter (3.43 Å) and one longer (3.44 Å) Ca(2)-Bi(2) bond length. Both Ca(2)-Bi(3) bond lengths are 3.25 Å. Both Ca(2)-Bi(4) bond lengths are 3.23 Å. In the third Ca site, Ca(3) is bonded in a 7-coordinate geometry to one Zn(1), one Bi(1), one Bi(4), two equivalent Bi(2), and two equivalent Bi(5) atoms. The Ca(3)-Zn(1) bond length is 3.29 Å. The Ca(3)-Bi(1) bond length is 3.43 Å. The Ca(3)-Bi(4) bond length is 3.33 Å. Both Ca(3)-Bi(2) bond lengths are 3.31 Å. Both Ca(3)-Bi(5) bond lengths are 3.38 Å. In the fourth Ca site, Ca(4) is bonded in a 7-coordinate geometry to two equivalent Zn(1), one Bi(2), two equivalent Bi(1), and two equivalent Bi(3) atoms. Both Ca(4)-Zn(1) bond lengths are 3.20 Å. The Ca(4)-Bi(2) bond length is 3.32 Å. Both Ca(4)-Bi(1) bond lengths are 3.18 Å. Both Ca(4)-Bi(3) bond lengths are 3.31 Å. In the fifth Ca site, Ca(5) is bonded in a 7-coordinate geometry to two equivalent Zn(1), two equivalent Zn(2), one Bi(5), two equivalent Bi(3), and two equivalent Bi(4) atoms. Both Ca(5)-Zn(1) bond lengths are 3.56 Å. Both Ca(5)-Zn(2) bond lengths are 3.20 Å. The Ca(5)-Bi(5) bond length is 3.32 Å. Both Ca(5)-Bi(3) bond lengths are 3.31 Å. Both Ca(5)-Bi(4) bond lengths are 3.24 Å. There are two inequivalent Zn sites. In the first Zn site, Zn(1) is bonded in a 10-coordinate geometry to one Ca(1), one Ca(3), two equivalent Ca(4), two equivalent Ca(5), one Bi(1), one Bi(3), and two equivalent Bi(5) atoms. The Zn(1)-Bi(1) bond length is 3.09 Å. The Zn(1)-Bi(3) bond length is 2.76 Å. Both Zn(1)-Bi(5) bond lengths are 2.81 Å. In the second Zn site, Zn(2) is bonded in a 6-coordinate geometry to two equivalent Ca(5), one Bi(3), one Bi(4), and two equivalent Bi(2) atoms. The Zn(2)-Bi(3) bond length is 2.90 Å. The Zn(2)-Bi(4) bond length is 2.84 Å. Both Zn(2)-Bi(2) bond lengths are 2.79 Å. There are five inequivalent Bi sites. In the first Bi site, Bi(3) is bonded in a 8-coordinate geometry to two equivalent Ca(2), two equivalent Ca(4), two equivalent Ca(5), one Zn(1), and one Zn(2) atom. In the second Bi site, Bi(4) is bonded to one Ca(1), one Ca(3), two equivalent Ca(2), two equivalent Ca(5), and one Zn(2) atom to form a mixture of distorted edge and corner-sharing BiCa6Zn pentagonal bipyramids. In the third Bi site, Bi(5) is bonded in a 7-coordinate geometry to one Ca(5), two equivalent Ca(1), two equivalent Ca(3), and two equivalent Zn(1) atoms. In the fourth Bi site, Bi(1) is bonded in a distorted body-centered cubic geometry to two equivalent Ca(3), four equivalent Ca(4), and two equivalent Zn(1) atoms. In the fifth Bi site, Bi(2) is bonded in a 7-coordinate geometry to one Ca(4), two equivalent Ca(2), two equivalent Ca(3), and two equivalent Zn(2) atoms.