Tm3Ag3Ga8 crystallizes in the orthorhombic Immm space group. There are two inequivalent Tm sites. In the first Tm site, Tm(1) is bonded to four equivalent Ga(1) and eight equivalent Ga(2) atoms to form TmGa12 cuboctahedra that share edges with two equivalent Ag(1)Tm4Ga4Ag4 cuboctahedra and faces with two equivalent Tm(1)Ga12 cuboctahedra. In the second Tm site, Tm(2) is bonded in a 14-coordinate geometry to two equivalent Ag(1), two equivalent Ag(2), four equivalent Ga(2), and six equivalent Ga(1) atoms. There are two inequivalent Ag sites. In the first Ag site, Ag(1) is bonded to four equivalent Tm(2), four equivalent Ag(2), and four equivalent Ga(1) atoms to form distorted AgTm4Ga4Ag4 cuboctahedra that share edges with two equivalent Tm(1)Ga12 cuboctahedra and faces with two equivalent Ag(1)Tm4Ga4Ag4 cuboctahedra. In the second Ag site, Ag(2) is bonded in a 10-coordinate geometry to two equivalent Tm(2), two equivalent Ag(1), two equivalent Ga(2), and four equivalent Ga(1) atoms. There are two inequivalent Ga sites. In the first Ga site, Ga(1) is bonded in a 10-coordinate geometry to one Tm(1), three equivalent Tm(2), one Ag(1), two equivalent Ag(2), and three equivalent Ga(2) atoms. In the second Ga site, Ga(2) is bonded in a 9-coordinate geometry to two equivalent Tm(1), two equivalent Tm(2), one Ag(2), one Ga(2), and three equivalent Ga(1) atoms.
Tm3Ag3Ga8 crystallizes in the orthorhombic Immm space group. There are two inequivalent Tm sites. In the first Tm site, Tm(1) is bonded to four equivalent Ga(1) and eight equivalent Ga(2) atoms to form TmGa12 cuboctahedra that share edges with two equivalent Ag(1)Tm4Ga4Ag4 cuboctahedra and faces with two equivalent Tm(1)Ga12 cuboctahedra. All Tm(1)-Ga(1) bond lengths are 3.24 Å. All Tm(1)-Ga(2) bond lengths are 3.21 Å. In the second Tm site, Tm(2) is bonded in a 14-coordinate geometry to two equivalent Ag(1), two equivalent Ag(2), four equivalent Ga(2), and six equivalent Ga(1) atoms. Both Tm(2)-Ag(1) bond lengths are 3.40 Å. Both Tm(2)-Ag(2) bond lengths are 3.16 Å. All Tm(2)-Ga(2) bond lengths are 3.07 Å. There are four shorter (3.12 Å) and two longer (3.32 Å) Tm(2)-Ga(1) bond lengths. There are two inequivalent Ag sites. In the first Ag site, Ag(1) is bonded to four equivalent Tm(2), four equivalent Ag(2), and four equivalent Ga(1) atoms to form distorted AgTm4Ga4Ag4 cuboctahedra that share edges with two equivalent Tm(1)Ga12 cuboctahedra and faces with two equivalent Ag(1)Tm4Ga4Ag4 cuboctahedra. All Ag(1)-Ag(2) bond lengths are 2.82 Å. All Ag(1)-Ga(1) bond lengths are 2.77 Å. In the second Ag site, Ag(2) is bonded in a 10-coordinate geometry to two equivalent Tm(2), two equivalent Ag(1), two equivalent Ga(2), and four equivalent Ga(1) atoms. Both Ag(2)-Ga(2) bond lengths are 2.65 Å. All Ag(2)-Ga(1) bond lengths are 2.85 Å. There are two inequivalent Ga sites. In the first Ga site, Ga(1) is bonded in a 10-coordinate geometry to one Tm(1), three equivalent Tm(2), one Ag(1), two equivalent Ag(2), and three equivalent Ga(2) atoms. There are two shorter (2.62 Å) and one longer (2.70 Å) Ga(1)-Ga(2) bond length. In the second Ga site, Ga(2) is bonded in a 9-coordinate geometry to two equivalent Tm(1), two equivalent Tm(2), one Ag(2), one Ga(2), and three equivalent Ga(1) atoms. The Ga(2)-Ga(2) bond length is 2.49 Å.