Eu3Ga8 crystallizes in the orthorhombic Immm space group. There are two inequivalent Eu sites. In the first Eu site, Eu(1) is bonded to four equivalent Ga(3) and eight equivalent Ga(2) atoms to form a mixture of face and edge-sharing EuGa12 cuboctahedra. In the second Eu site, Eu(2) is bonded in a 14-coordinate geometry to two equivalent Ga(2), four equivalent Ga(1), four equivalent Ga(3), and four equivalent Ga(4) atoms. There are four inequivalent Ga sites. In the first Ga site, Ga(1) is bonded in a 8-coordinate geometry to four equivalent Eu(2) and four equivalent Ga(4) atoms. In the second Ga site, Ga(2) is bonded in a 9-coordinate geometry to two equivalent Eu(2), four equivalent Eu(1), one Ga(2), and two equivalent Ga(3) atoms. In the third Ga site, Ga(3) is bonded in a 9-coordinate geometry to two equivalent Eu(1), four equivalent Eu(2), one Ga(4), and two equivalent Ga(2) atoms. In the fourth Ga site, Ga(4) is bonded in a 9-coordinate geometry to four equivalent Eu(2), one Ga(3), and four equivalent Ga(1) atoms.
Eu3Ga8 crystallizes in the orthorhombic Immm space group. There are two inequivalent Eu sites. In the first Eu site, Eu(1) is bonded to four equivalent Ga(3) and eight equivalent Ga(2) atoms to form a mixture of face and edge-sharing EuGa12 cuboctahedra. All Eu(1)-Ga(3) bond lengths are 3.32 Å. All Eu(1)-Ga(2) bond lengths are 3.40 Å. In the second Eu site, Eu(2) is bonded in a 14-coordinate geometry to two equivalent Ga(2), four equivalent Ga(1), four equivalent Ga(3), and four equivalent Ga(4) atoms. Both Eu(2)-Ga(2) bond lengths are 3.42 Å. There are two shorter (3.39 Å) and two longer (3.49 Å) Eu(2)-Ga(1) bond lengths. All Eu(2)-Ga(3) bond lengths are 3.45 Å. All Eu(2)-Ga(4) bond lengths are 3.36 Å. There are four inequivalent Ga sites. In the first Ga site, Ga(1) is bonded in a 8-coordinate geometry to four equivalent Eu(2) and four equivalent Ga(4) atoms. All Ga(1)-Ga(4) bond lengths are 2.68 Å. In the second Ga site, Ga(2) is bonded in a 9-coordinate geometry to two equivalent Eu(2), four equivalent Eu(1), one Ga(2), and two equivalent Ga(3) atoms. The Ga(2)-Ga(2) bond length is 2.47 Å. Both Ga(2)-Ga(3) bond lengths are 2.51 Å. In the third Ga site, Ga(3) is bonded in a 9-coordinate geometry to two equivalent Eu(1), four equivalent Eu(2), one Ga(4), and two equivalent Ga(2) atoms. The Ga(3)-Ga(4) bond length is 2.51 Å. In the fourth Ga site, Ga(4) is bonded in a 9-coordinate geometry to four equivalent Eu(2), one Ga(3), and four equivalent Ga(1) atoms.