Tb3Pt2Ga9 crystallizes in the orthorhombic Immm space group. There are two inequivalent Tb sites. In the first Tb site, Tb(1) is bonded to four equivalent Ga(3) and eight equivalent Ga(2) atoms to form TbGa12 cuboctahedra that share edges with two equivalent Ga(1)Tb4Ga4Pt4 cuboctahedra and faces with two equivalent Tb(1)Ga12 cuboctahedra. In the second Tb site, Tb(2) is bonded in a 14-coordinate geometry to two equivalent Pt(1), two equivalent Ga(1), four equivalent Ga(2), and six equivalent Ga(3) atoms. Pt(1) is bonded in a 10-coordinate geometry to two equivalent Tb(2), two equivalent Ga(1), two equivalent Ga(2), and four equivalent Ga(3) atoms. There are three inequivalent Ga sites. In the first Ga site, Ga(1) is bonded to four equivalent Tb(2), four equivalent Pt(1), and four equivalent Ga(3) atoms to form GaTb4Ga4Pt4 cuboctahedra that share edges with two equivalent Tb(1)Ga12 cuboctahedra and faces with two equivalent Ga(1)Tb4Ga4Pt4 cuboctahedra. In the second Ga site, Ga(2) is bonded in a 9-coordinate geometry to two equivalent Tb(1), two equivalent Tb(2), one Pt(1), one Ga(2), and three equivalent Ga(3) atoms. In the third Ga site, Ga(3) is bonded in a 10-coordinate geometry to one Tb(1), three equivalent Tb(2), two equivalent Pt(1), one Ga(1), and three equivalent Ga(2) atoms.
Tb3Pt2Ga9 crystallizes in the orthorhombic Immm space group. There are two inequivalent Tb sites. In the first Tb site, Tb(1) is bonded to four equivalent Ga(3) and eight equivalent Ga(2) atoms to form TbGa12 cuboctahedra that share edges with two equivalent Ga(1)Tb4Ga4Pt4 cuboctahedra and faces with two equivalent Tb(1)Ga12 cuboctahedra. All Tb(1)-Ga(3) bond lengths are 3.22 Å. All Tb(1)-Ga(2) bond lengths are 3.17 Å. In the second Tb site, Tb(2) is bonded in a 14-coordinate geometry to two equivalent Pt(1), two equivalent Ga(1), four equivalent Ga(2), and six equivalent Ga(3) atoms. Both Tb(2)-Pt(1) bond lengths are 3.07 Å. Both Tb(2)-Ga(1) bond lengths are 3.26 Å. All Tb(2)-Ga(2) bond lengths are 3.11 Å. There are four shorter (3.08 Å) and two longer (3.41 Å) Tb(2)-Ga(3) bond lengths. Pt(1) is bonded in a 10-coordinate geometry to two equivalent Tb(2), two equivalent Ga(1), two equivalent Ga(2), and four equivalent Ga(3) atoms. Both Pt(1)-Ga(1) bond lengths are 2.83 Å. Both Pt(1)-Ga(2) bond lengths are 2.59 Å. All Pt(1)-Ga(3) bond lengths are 2.78 Å. There are three inequivalent Ga sites. In the first Ga site, Ga(1) is bonded to four equivalent Tb(2), four equivalent Pt(1), and four equivalent Ga(3) atoms to form GaTb4Ga4Pt4 cuboctahedra that share edges with two equivalent Tb(1)Ga12 cuboctahedra and faces with two equivalent Ga(1)Tb4Ga4Pt4 cuboctahedra. All Ga(1)-Ga(3) bond lengths are 2.73 Å. In the second Ga site, Ga(2) is bonded in a 9-coordinate geometry to two equivalent Tb(1), two equivalent Tb(2), one Pt(1), one Ga(2), and three equivalent Ga(3) atoms. The Ga(2)-Ga(2) bond length is 2.53 Å. There are two shorter (2.59 Å) and one longer (2.70 Å) Ga(2)-Ga(3) bond length. In the third Ga site, Ga(3) is bonded in a 10-coordinate geometry to one Tb(1), three equivalent Tb(2), two equivalent Pt(1), one Ga(1), and three equivalent Ga(2) atoms.