Er2GeSi crystallizes in the orthorhombic Amm2 space group. There are two inequivalent Er sites. In the first Er site, Er(1) is bonded in a 7-coordinate geometry to three equivalent Ge(1) and four equivalent Si(1) atoms. In the second Er site, Er(2) is bonded in a 7-coordinate geometry to four equivalent Ge(1) and three equivalent Si(1) atoms. Ge(1) is bonded in a 9-coordinate geometry to three equivalent Er(1), four equivalent Er(2), and two equivalent Si(1) atoms. Si(1) is bonded in a 9-coordinate geometry to three equivalent Er(2), four equivalent Er(1), and two equivalent Ge(1) atoms.
Er2GeSi crystallizes in the orthorhombic Amm2 space group. There are two inequivalent Er sites. In the first Er site, Er(1) is bonded in a 7-coordinate geometry to three equivalent Ge(1) and four equivalent Si(1) atoms. There is one shorter (2.93 Å) and two longer (3.13 Å) Er(1)-Ge(1) bond lengths. All Er(1)-Si(1) bond lengths are 2.92 Å. In the second Er site, Er(2) is bonded in a 7-coordinate geometry to four equivalent Ge(1) and three equivalent Si(1) atoms. All Er(2)-Ge(1) bond lengths are 2.92 Å. There is one shorter (2.91 Å) and two longer (3.14 Å) Er(2)-Si(1) bond lengths. Ge(1) is bonded in a 9-coordinate geometry to three equivalent Er(1), four equivalent Er(2), and two equivalent Si(1) atoms. Both Ge(1)-Si(1) bond lengths are 2.57 Å. Si(1) is bonded in a 9-coordinate geometry to three equivalent Er(2), four equivalent Er(1), and two equivalent Ge(1) atoms.