Materials Data on Al2CdBr8 by Materials Project
CdAl2Br8 crystallizes in the monoclinic Pc space group. The structure is two-dimensional and consists of one CdAl2Br8 sheet oriented in the (0, 1, 0) direction. Cd2+ is bonded to six Br1- atoms to form CdBr6 octahedra that share corners with two AlBr4 tetrahedra and edges with two AlBr4 tetrahedra. There are a spread of Cd–Br bond distances ranging from 2.80–2.89 Å. There are two inequivalent Al3+ sites. In the first Al3+ site, Al3+ is bonded to four Br1- atoms to form AlBr4 tetrahedra that share a cornercorner with one CdBr6 octahedra and an edgeedge with one CdBr6 octahedra. The corner-sharing octahedral tilt angles are 59°. There are a spread of Al–Br bond distances ranging from 2.27–2.37 Å. In the second Al3+ site, Al3+ is bonded to four Br1- atoms to form AlBr4 tetrahedra that share a cornercorner with one CdBr6 octahedra and an edgeedge with one CdBr6 octahedra. The corner-sharing octahedral tilt angles are 60°. There are a spread of Al–Br bond distances ranging from 2.26–2.38 Å. There are eight inequivalent Br1- sites. In the first Br1- site, Br1- is bonded in a single-bond geometry to one Al3+ atom. In the second Br1- site, Br1- is bonded in an L-shaped geometry to one Cd2+ and one Al3+ atom. In the third Br1- site, Br1- is bonded in a single-bond geometry to one Al3+ atom. In the fourth Br1- site, Br1- is bonded in a bent 120 degrees geometry to one Cd2+ and one Al3+ atom. In the fifth Br1- site, Br1- is bonded in an L-shaped geometry to one Cd2+ and one Al3+ atom. In the sixth Br1- site, Br1- is bonded in a bent 120 degrees geometry to one Cd2+ and one Al3+ atom. In the seventh Br1- site, Br1- is bonded in an L-shaped geometry to one Cd2+ and one Al3+ atom. In the eighth Br1- site, Br1- is bonded in an L-shaped geometry to one Cd2+ and one Al3+ atom.