EuGaSn crystallizes in the hexagonal P6_3/mmc space group. There are two inequivalent Eu sites. In the first Eu site, Eu(1) is bonded to six equivalent Sn(1) atoms to form EuSn6 octahedra that share corners with six equivalent Ga(1)Eu3Sn3 octahedra, edges with six equivalent Eu(1)Sn6 octahedra, and edges with six equivalent Ga(1)Eu3Sn3 octahedra. The corner-sharing octahedral tilt angles are 21°. In the second Eu site, Eu(2) is bonded in a 6-coordinate geometry to six equivalent Ga(1) and six equivalent Sn(1) atoms. Ga(1) is bonded to three equivalent Eu(2) and three equivalent Sn(1) atoms to form distorted GaEu3Sn3 octahedra that share corners with three equivalent Eu(1)Sn6 octahedra, corners with six equivalent Ga(1)Eu3Sn3 octahedra, edges with three equivalent Eu(1)Sn6 octahedra, edges with six equivalent Ga(1)Eu3Sn3 octahedra, and  a faceface with one Ga(1)Eu3Sn3 octahedra. The corner-sharing octahedral tilt angles range from 21-51°. Sn(1) is bonded in a 9-coordinate geometry to three equivalent Eu(1), three equivalent Eu(2), and three equivalent Ga(1) atoms.
EuGaSn crystallizes in the hexagonal P6_3/mmc space group. There are two inequivalent Eu sites. In the first Eu site, Eu(1) is bonded to six equivalent Sn(1) atoms to form EuSn6 octahedra that share corners with six equivalent Ga(1)Eu3Sn3 octahedra, edges with six equivalent Eu(1)Sn6 octahedra, and edges with six equivalent Ga(1)Eu3Sn3 octahedra. The corner-sharing octahedral tilt angles are 21°. All Eu(1)-Sn(1) bond lengths are 3.35 Å. In the second Eu site, Eu(2) is bonded in a 6-coordinate geometry to six equivalent Ga(1) and six equivalent Sn(1) atoms. All Eu(2)-Ga(1) bond lengths are 3.06 Å. All Eu(2)-Sn(1) bond lengths are 3.57 Å. Ga(1) is bonded to three equivalent Eu(2) and three equivalent Sn(1) atoms to form distorted GaEu3Sn3 octahedra that share corners with three equivalent Eu(1)Sn6 octahedra, corners with six equivalent Ga(1)Eu3Sn3 octahedra, edges with three equivalent Eu(1)Sn6 octahedra, edges with six equivalent Ga(1)Eu3Sn3 octahedra, and  a faceface with one Ga(1)Eu3Sn3 octahedra. The corner-sharing octahedral tilt angles range from 21-51°. All Ga(1)-Sn(1) bond lengths are 2.75 Å. Sn(1) is bonded in a 9-coordinate geometry to three equivalent Eu(1), three equivalent Eu(2), and three equivalent Ga(1) atoms.