CaAlF5 crystallizes in the monoclinic C2/c space group. Ca(1) is bonded to one F(2), two equivalent F(1), and four equivalent F(3) atoms to form CaF7 pentagonal bipyramids that share corners with four equivalent Al(1)F6 octahedra, edges with two equivalent Al(1)F6 octahedra, and edges with two equivalent Ca(1)F7 pentagonal bipyramids. The corner-sharing octahedral tilt angles range from 1-36°. Al(1) is bonded to two equivalent F(1), two equivalent F(2), and two equivalent F(3) atoms to form AlF6 octahedra that share corners with two equivalent Al(1)F6 octahedra, corners with four equivalent Ca(1)F7 pentagonal bipyramids, and edges with two equivalent Ca(1)F7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 23°. There are three inequivalent F sites. In the first F site, F(1) is bonded in a linear geometry to one Ca(1) and one Al(1) atom. In the second F site, F(2) is bonded in a 3-coordinate geometry to one Ca(1) and two equivalent Al(1) atoms. In the third F site, F(3) is bonded in a 3-coordinate geometry to two equivalent Ca(1) and one Al(1) atom.
CaAlF5 crystallizes in the monoclinic C2/c space group. Ca(1) is bonded to one F(2), two equivalent F(1), and four equivalent F(3) atoms to form CaF7 pentagonal bipyramids that share corners with four equivalent Al(1)F6 octahedra, edges with two equivalent Al(1)F6 octahedra, and edges with two equivalent Ca(1)F7 pentagonal bipyramids. The corner-sharing octahedral tilt angles range from 1-36°. The Ca(1)-F(2) bond length is 2.49 Å. Both Ca(1)-F(1) bond lengths are 2.21 Å. There are two shorter (2.29 Å) and two longer (2.34 Å) Ca(1)-F(3) bond lengths. Al(1) is bonded to two equivalent F(1), two equivalent F(2), and two equivalent F(3) atoms to form AlF6 octahedra that share corners with two equivalent Al(1)F6 octahedra, corners with four equivalent Ca(1)F7 pentagonal bipyramids, and edges with two equivalent Ca(1)F7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 23°. Both Al(1)-F(1) bond lengths are 1.76 Å. Both Al(1)-F(2) bond lengths are 1.87 Å. Both Al(1)-F(3) bond lengths are 1.81 Å. There are three inequivalent F sites. In the first F site, F(1) is bonded in a linear geometry to one Ca(1) and one Al(1) atom. In the second F site, F(2) is bonded in a 3-coordinate geometry to one Ca(1) and two equivalent Al(1) atoms. In the third F site, F(3) is bonded in a 3-coordinate geometry to two equivalent Ca(1) and one Al(1) atom.