Ca3AlSb3 crystallizes in the orthorhombic Pnma space group. There are three inequivalent Ca sites. In the first Ca site, Ca(1) is bonded to one Sb(3), two equivalent Sb(1), and three equivalent Sb(2) atoms to form a mixture of distorted face, edge, and corner-sharing CaSb6 octahedra. The corner-sharing octahedral tilt angles range from 39-54°. In the second Ca site, Ca(2) is bonded to one Sb(2), two equivalent Sb(1), and three equivalent Sb(3) atoms to form a mixture of face, edge, and corner-sharing CaSb6 octahedra. The corner-sharing octahedral tilt angles range from 39-54°. In the third Ca site, Ca(3) is bonded in a 7-coordinate geometry to two equivalent Al(1), one Sb(3), two equivalent Sb(1), and two equivalent Sb(2) atoms. Al(1) is bonded in a 6-coordinate geometry to two equivalent Ca(3), one Sb(1), one Sb(2), and two equivalent Sb(3) atoms. There are three inequivalent Sb sites. In the first Sb site, Sb(1) is bonded to two equivalent Ca(1), two equivalent Ca(2), two equivalent Ca(3), and one Al(1) atom to form a mixture of distorted face, edge, and corner-sharing SbCa6Al pentagonal bipyramids. In the second Sb site, Sb(2) is bonded to one Ca(2), two equivalent Ca(3), three equivalent Ca(1), and one Al(1) atom to form a mixture of distorted face, edge, and corner-sharing SbCa6Al pentagonal bipyramids. In the third Sb site, Sb(3) is bonded in a 7-coordinate geometry to one Ca(1), one Ca(3), three equivalent Ca(2), and two equivalent Al(1) atoms.
Ca3AlSb3 crystallizes in the orthorhombic Pnma space group. There are three inequivalent Ca sites. In the first Ca site, Ca(1) is bonded to one Sb(3), two equivalent Sb(1), and three equivalent Sb(2) atoms to form a mixture of distorted face, edge, and corner-sharing CaSb6 octahedra. The corner-sharing octahedral tilt angles range from 39-54°. The Ca(1)-Sb(3) bond length is 3.44 Å. Both Ca(1)-Sb(1) bond lengths are 3.29 Å. There are two shorter (3.17 Å) and one longer (3.25 Å) Ca(1)-Sb(2) bond length. In the second Ca site, Ca(2) is bonded to one Sb(2), two equivalent Sb(1), and three equivalent Sb(3) atoms to form a mixture of face, edge, and corner-sharing CaSb6 octahedra. The corner-sharing octahedral tilt angles range from 39-54°. The Ca(2)-Sb(2) bond length is 3.42 Å. Both Ca(2)-Sb(1) bond lengths are 3.17 Å. There is one shorter (3.31 Å) and two longer (3.40 Å) Ca(2)-Sb(3) bond lengths. In the third Ca site, Ca(3) is bonded in a 7-coordinate geometry to two equivalent Al(1), one Sb(3), two equivalent Sb(1), and two equivalent Sb(2) atoms. Both Ca(3)-Al(1) bond lengths are 3.26 Å. The Ca(3)-Sb(3) bond length is 3.17 Å. Both Ca(3)-Sb(1) bond lengths are 3.24 Å. Both Ca(3)-Sb(2) bond lengths are 3.13 Å. Al(1) is bonded in a 6-coordinate geometry to two equivalent Ca(3), one Sb(1), one Sb(2), and two equivalent Sb(3) atoms. The Al(1)-Sb(1) bond length is 2.71 Å. The Al(1)-Sb(2) bond length is 2.73 Å. Both Al(1)-Sb(3) bond lengths are 2.76 Å. There are three inequivalent Sb sites. In the first Sb site, Sb(1) is bonded to two equivalent Ca(1), two equivalent Ca(2), two equivalent Ca(3), and one Al(1) atom to form a mixture of distorted face, edge, and corner-sharing SbCa6Al pentagonal bipyramids. In the second Sb site, Sb(2) is bonded to one Ca(2), two equivalent Ca(3), three equivalent Ca(1), and one Al(1) atom to form a mixture of distorted face, edge, and corner-sharing SbCa6Al pentagonal bipyramids. In the third Sb site, Sb(3) is bonded in a 7-coordinate geometry to one Ca(1), one Ca(3), three equivalent Ca(2), and two equivalent Al(1) atoms.