ErOsGe2 crystallizes in the orthorhombic Pbam space group. There are two inequivalent Er sites. In the first Er site, Er(1) is bonded in a 12-coordinate geometry to one Os(2), three equivalent Os(1), one Ge(4), one Ge(5), two equivalent Ge(1), two equivalent Ge(2), and two equivalent Ge(3) atoms. In the second Er site, Er(2) is bonded in a 7-coordinate geometry to two equivalent Os(2), four equivalent Os(1), two equivalent Ge(1), two equivalent Ge(3), and three equivalent Ge(5) atoms. There are two inequivalent Os sites. In the first Os site, Os(1) is bonded in a 12-coordinate geometry to two equivalent Er(2), three equivalent Er(1), one Os(2), one Ge(2), one Ge(3), one Ge(4), one Ge(5), and two equivalent Ge(1) atoms. In the second Os site, Os(2) is bonded in a 12-coordinate geometry to two equivalent Er(1), two equivalent Er(2), two equivalent Os(1), two equivalent Ge(1), two equivalent Ge(4), and two equivalent Ge(5) atoms. There are five inequivalent Ge sites. In the first Ge site, Ge(5) is bonded in a 9-coordinate geometry to two equivalent Er(1), three equivalent Er(2), two equivalent Os(1), and two equivalent Os(2) atoms. In the second Ge site, Ge(1) is bonded in a 7-coordinate geometry to one Er(2), two equivalent Er(1), one Os(2), two equivalent Os(1), and one Ge(1) atom. In the third Ge site, Ge(2) is bonded in a 7-coordinate geometry to four equivalent Er(1), two equivalent Os(1), and one Ge(2) atom. In the fourth Ge site, Ge(3) is bonded in a 9-coordinate geometry to two equivalent Er(2), four equivalent Er(1), two equivalent Os(1), and one Ge(3) atom. In the fifth Ge site, Ge(4) is bonded in a 6-coordinate geometry to two equivalent Er(1), two equivalent Os(1), and two equivalent Os(2) atoms.
ErOsGe2 crystallizes in the orthorhombic Pbam space group. There are two inequivalent Er sites. In the first Er site, Er(1) is bonded in a 12-coordinate geometry to one Os(2), three equivalent Os(1), one Ge(4), one Ge(5), two equivalent Ge(1), two equivalent Ge(2), and two equivalent Ge(3) atoms. The Er(1)-Os(2) bond length is 3.17 Å. There are a spread of Er(1)-Os(1) bond distances ranging from 3.18-3.25 Å. The Er(1)-Ge(4) bond length is 2.89 Å. The Er(1)-Ge(5) bond length is 2.83 Å. There is one shorter (2.99 Å) and one longer (3.04 Å) Er(1)-Ge(1) bond length. There is one shorter (3.06 Å) and one longer (3.11 Å) Er(1)-Ge(2) bond length. There is one shorter (3.00 Å) and one longer (3.04 Å) Er(1)-Ge(3) bond length. In the second Er site, Er(2) is bonded in a 7-coordinate geometry to two equivalent Os(2), four equivalent Os(1), two equivalent Ge(1), two equivalent Ge(3), and three equivalent Ge(5) atoms. Both Er(2)-Os(2) bond lengths are 3.22 Å. There are two shorter (3.24 Å) and two longer (3.34 Å) Er(2)-Os(1) bond lengths. Both Er(2)-Ge(1) bond lengths are 2.92 Å. There is one shorter (2.91 Å) and one longer (2.95 Å) Er(2)-Ge(3) bond length. There are a spread of Er(2)-Ge(5) bond distances ranging from 2.95-3.08 Å. There are two inequivalent Os sites. In the first Os site, Os(1) is bonded in a 12-coordinate geometry to two equivalent Er(2), three equivalent Er(1), one Os(2), one Ge(2), one Ge(3), one Ge(4), one Ge(5), and two equivalent Ge(1) atoms. The Os(1)-Os(2) bond length is 2.90 Å. The Os(1)-Ge(2) bond length is 2.48 Å. The Os(1)-Ge(3) bond length is 2.50 Å. The Os(1)-Ge(4) bond length is 2.75 Å. The Os(1)-Ge(5) bond length is 2.73 Å. There is one shorter (2.65 Å) and one longer (2.67 Å) Os(1)-Ge(1) bond length. In the second Os site, Os(2) is bonded in a 12-coordinate geometry to two equivalent Er(1), two equivalent Er(2), two equivalent Os(1), two equivalent Ge(1), two equivalent Ge(4), and two equivalent Ge(5) atoms. Both Os(2)-Ge(1) bond lengths are 2.58 Å. Both Os(2)-Ge(4) bond lengths are 2.64 Å. Both Os(2)-Ge(5) bond lengths are 2.66 Å. There are five inequivalent Ge sites. In the first Ge site, Ge(5) is bonded in a 9-coordinate geometry to two equivalent Er(1), three equivalent Er(2), two equivalent Os(1), and two equivalent Os(2) atoms. In the second Ge site, Ge(1) is bonded in a 7-coordinate geometry to one Er(2), two equivalent Er(1), one Os(2), two equivalent Os(1), and one Ge(1) atom. The Ge(1)-Ge(1) bond length is 2.53 Å. In the third Ge site, Ge(2) is bonded in a 7-coordinate geometry to four equivalent Er(1), two equivalent Os(1), and one Ge(2) atom. The Ge(2)-Ge(2) bond length is 2.66 Å. In the fourth Ge site, Ge(3) is bonded in a 9-coordinate geometry to two equivalent Er(2), four equivalent Er(1), two equivalent Os(1), and one Ge(3) atom. The Ge(3)-Ge(3) bond length is 2.62 Å. In the fifth Ge site, Ge(4) is bonded in a 6-coordinate geometry to two equivalent Er(1), two equivalent Os(1), and two equivalent Os(2) atoms.