Er2Au is Cotunnite structured and crystallizes in the orthorhombic Pnma space group. There are two inequivalent Er sites. In the first Er site, Er(1) is bonded to four equivalent Au(1) atoms to form a mixture of edge and corner-sharing ErAu4 tetrahedra. In the second Er site, Er(2) is bonded in a 3-coordinate geometry to five equivalent Au(1) atoms. Au(1) is bonded in a 9-coordinate geometry to four equivalent Er(1) and five equivalent Er(2) atoms.
Er2Au is Cotunnite structured and crystallizes in the orthorhombic Pnma space group. There are two inequivalent Er sites. In the first Er site, Er(1) is bonded to four equivalent Au(1) atoms to form a mixture of edge and corner-sharing ErAu4 tetrahedra. There are a spread of Er(1)-Au(1) bond distances ranging from 2.84-3.01 Å. In the second Er site, Er(2) is bonded in a 3-coordinate geometry to five equivalent Au(1) atoms. There are a spread of Er(2)-Au(1) bond distances ranging from 2.89-3.59 Å. Au(1) is bonded in a 9-coordinate geometry to four equivalent Er(1) and five equivalent Er(2) atoms.