Ca11Sb10 crystallizes in the tetragonal I4/mmm space group. There are four inequivalent Ca sites. In the first Ca site, Ca(1) is bonded to one Sb(1), one Sb(2), one Sb(4), and four equivalent Sb(5) atoms to form a mixture of distorted face, corner, and edge-sharing CaSb7 pentagonal bipyramids. In the second Ca site, Ca(2) is bonded in a 7-coordinate geometry to one Sb(3), two equivalent Sb(1), two equivalent Sb(2), and two equivalent Sb(5) atoms. In the third Ca site, Ca(3) is bonded in a 9-coordinate geometry to one Sb(2), four equivalent Sb(3), and four equivalent Sb(5) atoms. In the fourth Ca site, Ca(4) is bonded in a 7-coordinate geometry to one Sb(4), two equivalent Sb(1), two equivalent Sb(3), and two equivalent Sb(5) atoms. There are five inequivalent Sb sites. In the first Sb site, Sb(1) is bonded in a 8-coordinate geometry to two equivalent Ca(1), two equivalent Ca(2), and four equivalent Ca(4) atoms. In the second Sb site, Sb(2) is bonded in a 9-coordinate geometry to one Ca(3), four equivalent Ca(1), and four equivalent Ca(2) atoms. In the third Sb site, Sb(3) is bonded in a 11-coordinate geometry to one Ca(2), two equivalent Ca(3), four equivalent Ca(4), two equivalent Sb(3), and two equivalent Sb(5) atoms. In the fourth Sb site, Sb(4) is bonded in a 8-coordinate geometry to four equivalent Ca(1) and four equivalent Ca(4) atoms. In the fifth Sb site, Sb(5) is bonded in a 10-coordinate geometry to one Ca(2), one Ca(3), two equivalent Ca(4), four equivalent Ca(1), one Sb(3), and one Sb(5) atom.
Ca11Sb10 crystallizes in the tetragonal I4/mmm space group. There are four inequivalent Ca sites. In the first Ca site, Ca(1) is bonded to one Sb(1), one Sb(2), one Sb(4), and four equivalent Sb(5) atoms to form a mixture of distorted face, corner, and edge-sharing CaSb7 pentagonal bipyramids. The Ca(1)-Sb(1) bond length is 3.46 Å. The Ca(1)-Sb(2) bond length is 3.20 Å. The Ca(1)-Sb(4) bond length is 3.16 Å. There are two shorter (3.45 Å) and two longer (3.58 Å) Ca(1)-Sb(5) bond lengths. In the second Ca site, Ca(2) is bonded in a 7-coordinate geometry to one Sb(3), two equivalent Sb(1), two equivalent Sb(2), and two equivalent Sb(5) atoms. The Ca(2)-Sb(3) bond length is 3.55 Å. Both Ca(2)-Sb(1) bond lengths are 2.96 Å. Both Ca(2)-Sb(2) bond lengths are 3.57 Å. Both Ca(2)-Sb(5) bond lengths are 3.73 Å. In the third Ca site, Ca(3) is bonded in a 9-coordinate geometry to one Sb(2), four equivalent Sb(3), and four equivalent Sb(5) atoms. The Ca(3)-Sb(2) bond length is 3.56 Å. All Ca(3)-Sb(3) bond lengths are 3.57 Å. All Ca(3)-Sb(5) bond lengths are 3.50 Å. In the fourth Ca site, Ca(4) is bonded in a 7-coordinate geometry to one Sb(4), two equivalent Sb(1), two equivalent Sb(3), and two equivalent Sb(5) atoms. The Ca(4)-Sb(4) bond length is 3.18 Å. Both Ca(4)-Sb(1) bond lengths are 3.20 Å. Both Ca(4)-Sb(3) bond lengths are 3.47 Å. Both Ca(4)-Sb(5) bond lengths are 3.20 Å. There are five inequivalent Sb sites. In the first Sb site, Sb(1) is bonded in a 8-coordinate geometry to two equivalent Ca(1), two equivalent Ca(2), and four equivalent Ca(4) atoms. In the second Sb site, Sb(2) is bonded in a 9-coordinate geometry to one Ca(3), four equivalent Ca(1), and four equivalent Ca(2) atoms. In the third Sb site, Sb(3) is bonded in a 11-coordinate geometry to one Ca(2), two equivalent Ca(3), four equivalent Ca(4), two equivalent Sb(3), and two equivalent Sb(5) atoms. Both Sb(3)-Sb(3) bond lengths are 3.04 Å. Both Sb(3)-Sb(5) bond lengths are 3.31 Å. In the fourth Sb site, Sb(4) is bonded in a 8-coordinate geometry to four equivalent Ca(1) and four equivalent Ca(4) atoms. In the fifth Sb site, Sb(5) is bonded in a 10-coordinate geometry to one Ca(2), one Ca(3), two equivalent Ca(4), four equivalent Ca(1), one Sb(3), and one Sb(5) atom. The Sb(5)-Sb(5) bond length is 2.99 Å.