Er(MnGa)6 crystallizes in the orthorhombic Fmmm space group. Er(1) is bonded in a 20-coordinate geometry to four equivalent Mn(1), four equivalent Mn(2), four equivalent Ga(2), and eight equivalent Ga(1) atoms. There are two inequivalent Mn sites. In the first Mn site, Mn(1) is bonded in a 4-coordinate geometry to two equivalent Er(1), four equivalent Mn(2), and four equivalent Ga(1) atoms. In the second Mn site, Mn(2) is bonded in a 10-coordinate geometry to one Er(1), one Mn(2), two equivalent Mn(1), two equivalent Ga(2), and four equivalent Ga(1) atoms. There are two inequivalent Ga sites. In the first Ga site, Ga(2) is bonded to two equivalent Er(1), four equivalent Mn(2), two equivalent Ga(2), and four equivalent Ga(1) atoms to form a mixture of distorted face and corner-sharing GaEr2Mn4Ga6 cuboctahedra. In the second Ga site, Ga(1) is bonded in a 10-coordinate geometry to two equivalent Er(1), two equivalent Mn(1), four equivalent Mn(2), and two equivalent Ga(2) atoms.
Er(MnGa)6 crystallizes in the orthorhombic Fmmm space group. Er(1) is bonded in a 20-coordinate geometry to four equivalent Mn(1), four equivalent Mn(2), four equivalent Ga(2), and eight equivalent Ga(1) atoms. All Er(1)-Mn(1) bond lengths are 3.35 Å. All Er(1)-Mn(2) bond lengths are 3.12 Å. All Er(1)-Ga(2) bond lengths are 3.42 Å. All Er(1)-Ga(1) bond lengths are 3.31 Å. There are two inequivalent Mn sites. In the first Mn site, Mn(1) is bonded in a 4-coordinate geometry to two equivalent Er(1), four equivalent Mn(2), and four equivalent Ga(1) atoms. All Mn(1)-Mn(2) bond lengths are 2.71 Å. All Mn(1)-Ga(1) bond lengths are 2.46 Å. In the second Mn site, Mn(2) is bonded in a 10-coordinate geometry to one Er(1), one Mn(2), two equivalent Mn(1), two equivalent Ga(2), and four equivalent Ga(1) atoms. The Mn(2)-Mn(2) bond length is 2.69 Å. Both Mn(2)-Ga(2) bond lengths are 2.68 Å. There are a spread of Mn(2)-Ga(1) bond distances ranging from 2.53-2.68 Å. There are two inequivalent Ga sites. In the first Ga site, Ga(2) is bonded to two equivalent Er(1), four equivalent Mn(2), two equivalent Ga(2), and four equivalent Ga(1) atoms to form a mixture of distorted face and corner-sharing GaEr2Mn4Ga6 cuboctahedra. Both Ga(2)-Ga(2) bond lengths are 2.44 Å. All Ga(2)-Ga(1) bond lengths are 2.63 Å. In the second Ga site, Ga(1) is bonded in a 10-coordinate geometry to two equivalent Er(1), two equivalent Mn(1), four equivalent Mn(2), and two equivalent Ga(2) atoms.