TmRuGa3 crystallizes in the cubic Pm-3m space group. Tm(1) is bonded in a 14-coordinate geometry to four equivalent Ru(1), two equivalent Ga(1), and eight equivalent Ga(2) atoms. Ru(1) is bonded to four equivalent Tm(1) and eight equivalent Ga(2) atoms to form distorted RuTm4Ga8 cuboctahedra that share corners with four equivalent Ru(1)Tm4Ga8 cuboctahedra, edges with four equivalent Ga(1)Tm6 octahedra, and faces with eight equivalent Ru(1)Tm4Ga8 cuboctahedra. There are two inequivalent Ga sites. In the first Ga site, Ga(1) is bonded to six equivalent Tm(1) atoms to form GaTm6 octahedra that share corners with six equivalent Ga(1)Tm6 octahedra and edges with twelve equivalent Ru(1)Tm4Ga8 cuboctahedra. The corner-sharing octahedra are not tilted. In the second Ga site, Ga(2) is bonded in a 9-coordinate geometry to three equivalent Tm(1), three equivalent Ru(1), and three equivalent Ga(2) atoms.
TmRuGa3 crystallizes in the cubic Pm-3m space group. Tm(1) is bonded in a 14-coordinate geometry to four equivalent Ru(1), two equivalent Ga(1), and eight equivalent Ga(2) atoms. All Tm(1)-Ru(1) bond lengths are 3.17 Å. Both Tm(1)-Ga(1) bond lengths are 3.17 Å. All Tm(1)-Ga(2) bond lengths are 2.91 Å. Ru(1) is bonded to four equivalent Tm(1) and eight equivalent Ga(2) atoms to form distorted RuTm4Ga8 cuboctahedra that share corners with four equivalent Ru(1)Tm4Ga8 cuboctahedra, edges with four equivalent Ga(1)Tm6 octahedra, and faces with eight equivalent Ru(1)Tm4Ga8 cuboctahedra. All Ru(1)-Ga(2) bond lengths are 2.63 Å. There are two inequivalent Ga sites. In the first Ga site, Ga(1) is bonded to six equivalent Tm(1) atoms to form GaTm6 octahedra that share corners with six equivalent Ga(1)Tm6 octahedra and edges with twelve equivalent Ru(1)Tm4Ga8 cuboctahedra. The corner-sharing octahedra are not tilted. In the second Ga site, Ga(2) is bonded in a 9-coordinate geometry to three equivalent Tm(1), three equivalent Ru(1), and three equivalent Ga(2) atoms. All Ga(2)-Ga(2) bond lengths are 2.67 Å.