EuAl2S4 crystallizes in the orthorhombic Cccm space group. Eu(1) is bonded in a 8-coordinate geometry to four equivalent S(1) and four equivalent S(2) atoms. Al(1) is bonded to two equivalent S(1) and two equivalent S(2) atoms to form edge-sharing AlS4 tetrahedra. There are two inequivalent S sites. In the first S site, S(2) is bonded in a 4-coordinate geometry to two equivalent Eu(1) and two equivalent Al(1) atoms. In the second S site, S(1) is bonded to two equivalent Eu(1) and two equivalent Al(1) atoms to form a mixture of distorted corner and edge-sharing SEu2Al2 trigonal pyramids.
EuAl2S4 crystallizes in the orthorhombic Cccm space group. Eu(1) is bonded in a 8-coordinate geometry to four equivalent S(1) and four equivalent S(2) atoms. All Eu(1)-S(1) bond lengths are 3.10 Å. All Eu(1)-S(2) bond lengths are 3.13 Å. Al(1) is bonded to two equivalent S(1) and two equivalent S(2) atoms to form edge-sharing AlS4 tetrahedra. There is one shorter (2.24 Å) and one longer (2.28 Å) Al(1)-S(1) bond length. Both Al(1)-S(2) bond lengths are 2.26 Å. There are two inequivalent S sites. In the first S site, S(2) is bonded in a 4-coordinate geometry to two equivalent Eu(1) and two equivalent Al(1) atoms. In the second S site, S(1) is bonded to two equivalent Eu(1) and two equivalent Al(1) atoms to form a mixture of distorted corner and edge-sharing SEu2Al2 trigonal pyramids.