ErMnSn2 crystallizes in the orthorhombic Pbam space group. There are two inequivalent Er sites. In the first Er site, Er(1) is bonded in a 8-coordinate geometry to one Sn(4), one Sn(5), two equivalent Sn(1), two equivalent Sn(2), and two equivalent Sn(3) atoms. In the second Er site, Er(2) is bonded to two equivalent Sn(1), two equivalent Sn(3), and three equivalent Sn(5) atoms to form a mixture of distorted corner and edge-sharing ErSn7 pentagonal bipyramids. There are two inequivalent Mn sites. In the first Mn site, Mn(1) is bonded in a 6-coordinate geometry to one Sn(2), one Sn(3), one Sn(4), one Sn(5), and two equivalent Sn(1) atoms. In the second Mn site, Mn(2) is bonded in a 6-coordinate geometry to two equivalent Sn(1), two equivalent Sn(4), and two equivalent Sn(5) atoms. There are five inequivalent Sn sites. In the first Sn site, Sn(2) is bonded in a 2-coordinate geometry to four equivalent Er(1) and two equivalent Mn(1) atoms. In the second Sn site, Sn(3) is bonded in a 8-coordinate geometry to two equivalent Er(2), four equivalent Er(1), and two equivalent Mn(1) atoms. In the third Sn site, Sn(4) is bonded in a 6-coordinate geometry to two equivalent Er(1), two equivalent Mn(1), and two equivalent Mn(2) atoms. In the fourth Sn site, Sn(5) is bonded in a 9-coordinate geometry to two equivalent Er(1), three equivalent Er(2), two equivalent Mn(1), and two equivalent Mn(2) atoms. In the fifth Sn site, Sn(1) is bonded in a 7-coordinate geometry to one Er(2), two equivalent Er(1), one Mn(2), two equivalent Mn(1), and one Sn(1) atom.
ErMnSn2 crystallizes in the orthorhombic Pbam space group. There are two inequivalent Er sites. In the first Er site, Er(1) is bonded in a 8-coordinate geometry to one Sn(4), one Sn(5), two equivalent Sn(1), two equivalent Sn(2), and two equivalent Sn(3) atoms. The Er(1)-Sn(4) bond length is 3.17 Å. The Er(1)-Sn(5) bond length is 3.06 Å. There is one shorter (3.20 Å) and one longer (3.24 Å) Er(1)-Sn(1) bond length. There is one shorter (3.32 Å) and one longer (3.33 Å) Er(1)-Sn(2) bond length. There is one shorter (3.20 Å) and one longer (3.21 Å) Er(1)-Sn(3) bond length. In the second Er site, Er(2) is bonded to two equivalent Sn(1), two equivalent Sn(3), and three equivalent Sn(5) atoms to form a mixture of distorted corner and edge-sharing ErSn7 pentagonal bipyramids. Both Er(2)-Sn(1) bond lengths are 3.03 Å. There is one shorter (3.10 Å) and one longer (3.12 Å) Er(2)-Sn(3) bond length. There are a spread of Er(2)-Sn(5) bond distances ranging from 3.16-3.28 Å. There are two inequivalent Mn sites. In the first Mn site, Mn(1) is bonded in a 6-coordinate geometry to one Sn(2), one Sn(3), one Sn(4), one Sn(5), and two equivalent Sn(1) atoms. The Mn(1)-Sn(2) bond length is 2.72 Å. The Mn(1)-Sn(3) bond length is 2.72 Å. The Mn(1)-Sn(4) bond length is 2.88 Å. The Mn(1)-Sn(5) bond length is 2.82 Å. Both Mn(1)-Sn(1) bond lengths are 2.82 Å. In the second Mn site, Mn(2) is bonded in a 6-coordinate geometry to two equivalent Sn(1), two equivalent Sn(4), and two equivalent Sn(5) atoms. Both Mn(2)-Sn(1) bond lengths are 2.78 Å. Both Mn(2)-Sn(4) bond lengths are 2.86 Å. Both Mn(2)-Sn(5) bond lengths are 2.81 Å. There are five inequivalent Sn sites. In the first Sn site, Sn(2) is bonded in a 2-coordinate geometry to four equivalent Er(1) and two equivalent Mn(1) atoms. In the second Sn site, Sn(3) is bonded in a 8-coordinate geometry to two equivalent Er(2), four equivalent Er(1), and two equivalent Mn(1) atoms. In the third Sn site, Sn(4) is bonded in a 6-coordinate geometry to two equivalent Er(1), two equivalent Mn(1), and two equivalent Mn(2) atoms. In the fourth Sn site, Sn(5) is bonded in a 9-coordinate geometry to two equivalent Er(1), three equivalent Er(2), two equivalent Mn(1), and two equivalent Mn(2) atoms. In the fifth Sn site, Sn(1) is bonded in a 7-coordinate geometry to one Er(2), two equivalent Er(1), one Mn(2), two equivalent Mn(1), and one Sn(1) atom. The Sn(1)-Sn(1) bond length is 2.92 Å.