Al2PbSe4 crystallizes in the orthorhombic Cccm space group. Al(1) is bonded to two equivalent Se(1) and two equivalent Se(2) atoms to form edge-sharing AlSe4 tetrahedra. Pb(1) is bonded in a 8-coordinate geometry to four equivalent Se(1) and four equivalent Se(2) atoms. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded in a distorted L-shaped geometry to two equivalent Al(1) and two equivalent Pb(1) atoms. In the second Se site, Se(2) is bonded in a distorted L-shaped geometry to two equivalent Al(1) and two equivalent Pb(1) atoms.
Al2PbSe4 crystallizes in the orthorhombic Cccm space group. Al(1) is bonded to two equivalent Se(1) and two equivalent Se(2) atoms to form edge-sharing AlSe4 tetrahedra. Both Al(1)-Se(1) bond lengths are 2.40 Å. There is one shorter (2.39 Å) and one longer (2.42 Å) Al(1)-Se(2) bond length. Pb(1) is bonded in a 8-coordinate geometry to four equivalent Se(1) and four equivalent Se(2) atoms. All Pb(1)-Se(1) bond lengths are 3.27 Å. All Pb(1)-Se(2) bond lengths are 3.23 Å. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded in a distorted L-shaped geometry to two equivalent Al(1) and two equivalent Pb(1) atoms. In the second Se site, Se(2) is bonded in a distorted L-shaped geometry to two equivalent Al(1) and two equivalent Pb(1) atoms.