Er5Pb4 crystallizes in the orthorhombic Pnma space group. There are three inequivalent Er sites. In the first Er site, Er(1) is bonded to one Pb(3), two equivalent Pb(2), and three equivalent Pb(1) atoms to form a mixture of distorted edge, corner, and face-sharing ErPb6 pentagonal pyramids. The corner-sharing octahedral tilt angles range from 39-41°. In the second Er site, Er(2) is bonded in a 7-coordinate geometry to one Pb(2), two equivalent Pb(3), and four equivalent Pb(1) atoms. In the third Er site, Er(3) is bonded to two equivalent Pb(1), two equivalent Pb(2), and two equivalent Pb(3) atoms to form a mixture of corner and face-sharing ErPb6 octahedra. The corner-sharing octahedral tilt angles range from 46-51°. There are three inequivalent Pb sites. In the first Pb site, Pb(3) is bonded in a 8-coordinate geometry to two equivalent Er(1), two equivalent Er(3), and four equivalent Er(2) atoms. In the second Pb site, Pb(1) is bonded in a 8-coordinate geometry to one Er(3), three equivalent Er(1), and four equivalent Er(2) atoms. In the third Pb site, Pb(2) is bonded in a 8-coordinate geometry to two equivalent Er(2), two equivalent Er(3), and four equivalent Er(1) atoms.
Er5Pb4 crystallizes in the orthorhombic Pnma space group. There are three inequivalent Er sites. In the first Er site, Er(1) is bonded to one Pb(3), two equivalent Pb(2), and three equivalent Pb(1) atoms to form a mixture of distorted edge, corner, and face-sharing ErPb6 pentagonal pyramids. The corner-sharing octahedral tilt angles range from 39-41°. The Er(1)-Pb(3) bond length is 3.27 Å. There is one shorter (3.10 Å) and one longer (3.22 Å) Er(1)-Pb(2) bond length. There are two shorter (3.08 Å) and one longer (3.21 Å) Er(1)-Pb(1) bond length. In the second Er site, Er(2) is bonded in a 7-coordinate geometry to one Pb(2), two equivalent Pb(3), and four equivalent Pb(1) atoms. The Er(2)-Pb(2) bond length is 3.43 Å. There is one shorter (3.13 Å) and one longer (3.45 Å) Er(2)-Pb(3) bond length. There are a spread of Er(2)-Pb(1) bond distances ranging from 3.21-3.86 Å. In the third Er site, Er(3) is bonded to two equivalent Pb(1), two equivalent Pb(2), and two equivalent Pb(3) atoms to form a mixture of corner and face-sharing ErPb6 octahedra. The corner-sharing octahedral tilt angles range from 46-51°. Both Er(3)-Pb(1) bond lengths are 3.24 Å. There is one shorter (3.12 Å) and one longer (3.22 Å) Er(3)-Pb(2) bond length. There is one shorter (3.09 Å) and one longer (3.22 Å) Er(3)-Pb(3) bond length. There are three inequivalent Pb sites. In the first Pb site, Pb(3) is bonded in a 8-coordinate geometry to two equivalent Er(1), two equivalent Er(3), and four equivalent Er(2) atoms. In the second Pb site, Pb(1) is bonded in a 8-coordinate geometry to one Er(3), three equivalent Er(1), and four equivalent Er(2) atoms. In the third Pb site, Pb(2) is bonded in a 8-coordinate geometry to two equivalent Er(2), two equivalent Er(3), and four equivalent Er(1) atoms.