Eu2Sb3 is Magnesium tetraboride-like structured and crystallizes in the monoclinic P2/c space group. There are five inequivalent Eu sites. In the first Eu site, Eu(1) is bonded in a 8-coordinate geometry to two equivalent Sb(1), two equivalent Sb(2), and four equivalent Sb(4) atoms. In the second Eu site, Eu(2) is bonded in a 8-coordinate geometry to one Sb(2), one Sb(3), one Sb(6), two equivalent Sb(1), two equivalent Sb(4), and two equivalent Sb(5) atoms. In the third Eu site, Eu(3) is bonded in a 8-coordinate geometry to two equivalent Sb(1), two equivalent Sb(3), two equivalent Sb(5), and four equivalent Sb(6) atoms. In the fourth Eu site, Eu(4) is bonded in a 8-coordinate geometry to one Sb(2), one Sb(4), one Sb(6), two equivalent Sb(1), and three equivalent Sb(3) atoms. In the fifth Eu site, Eu(5) is bonded in a 8-coordinate geometry to one Sb(3), one Sb(4), one Sb(6), two equivalent Sb(5), and three equivalent Sb(2) atoms. There are six inequivalent Sb sites. In the first Sb site, Sb(5) is bonded in a 8-coordinate geometry to one Eu(3), two equivalent Eu(2), two equivalent Eu(5), one Sb(1), one Sb(2), and one Sb(6) atom. In the second Sb site, Sb(6) is bonded in a 8-coordinate geometry to one Eu(2), one Eu(4), one Eu(5), two equivalent Eu(3), one Sb(3), one Sb(5), and one Sb(6) atom. In the third Sb site, Sb(1) is bonded in a 9-coordinate geometry to one Eu(1), one Eu(3), two equivalent Eu(2), two equivalent Eu(4), one Sb(3), one Sb(4), and one Sb(5) atom. In the fourth Sb site, Sb(2) is bonded in a 8-coordinate geometry to one Eu(1), one Eu(2), one Eu(4), three equivalent Eu(5), one Sb(4), and one Sb(5) atom. In the fifth Sb site, Sb(3) is bonded in a 8-coordinate geometry to one Eu(2), one Eu(3), one Eu(5), three equivalent Eu(4), one Sb(1), and one Sb(6) atom. In the sixth Sb site, Sb(4) is bonded in a 9-coordinate geometry to one Eu(4), one Eu(5), two equivalent Eu(1), two equivalent Eu(2), one Sb(1), one Sb(2), and one Sb(4) atom.
Eu2Sb3 is Magnesium tetraboride-like structured and crystallizes in the monoclinic P2/c space group. There are five inequivalent Eu sites. In the first Eu site, Eu(1) is bonded in a 8-coordinate geometry to two equivalent Sb(1), two equivalent Sb(2), and four equivalent Sb(4) atoms. Both Eu(1)-Sb(1) bond lengths are 3.30 Å. Both Eu(1)-Sb(2) bond lengths are 3.38 Å. There are two shorter (3.43 Å) and two longer (3.66 Å) Eu(1)-Sb(4) bond lengths. In the second Eu site, Eu(2) is bonded in a 8-coordinate geometry to one Sb(2), one Sb(3), one Sb(6), two equivalent Sb(1), two equivalent Sb(4), and two equivalent Sb(5) atoms. The Eu(2)-Sb(2) bond length is 3.36 Å. The Eu(2)-Sb(3) bond length is 3.43 Å. The Eu(2)-Sb(6) bond length is 3.32 Å. There is one shorter (3.43 Å) and one longer (3.56 Å) Eu(2)-Sb(1) bond length. There is one shorter (3.28 Å) and one longer (3.97 Å) Eu(2)-Sb(4) bond length. There is one shorter (3.39 Å) and one longer (3.79 Å) Eu(2)-Sb(5) bond length. In the third Eu site, Eu(3) is bonded in a 8-coordinate geometry to two equivalent Sb(1), two equivalent Sb(3), two equivalent Sb(5), and four equivalent Sb(6) atoms. Both Eu(3)-Sb(1) bond lengths are 3.97 Å. Both Eu(3)-Sb(3) bond lengths are 3.38 Å. Both Eu(3)-Sb(5) bond lengths are 3.29 Å. There are two shorter (3.45 Å) and two longer (3.62 Å) Eu(3)-Sb(6) bond lengths. In the fourth Eu site, Eu(4) is bonded in a 8-coordinate geometry to one Sb(2), one Sb(4), one Sb(6), two equivalent Sb(1), and three equivalent Sb(3) atoms. The Eu(4)-Sb(2) bond length is 3.45 Å. The Eu(4)-Sb(4) bond length is 3.35 Å. The Eu(4)-Sb(6) bond length is 3.30 Å. There is one shorter (3.29 Å) and one longer (3.40 Å) Eu(4)-Sb(1) bond length. There are a spread of Eu(4)-Sb(3) bond distances ranging from 3.33-3.40 Å. In the fifth Eu site, Eu(5) is bonded in a 8-coordinate geometry to one Sb(3), one Sb(4), one Sb(6), two equivalent Sb(5), and three equivalent Sb(2) atoms. The Eu(5)-Sb(3) bond length is 3.48 Å. The Eu(5)-Sb(4) bond length is 3.27 Å. The Eu(5)-Sb(6) bond length is 3.34 Å. There is one shorter (3.31 Å) and one longer (3.32 Å) Eu(5)-Sb(5) bond length. There are a spread of Eu(5)-Sb(2) bond distances ranging from 3.35-3.51 Å. There are six inequivalent Sb sites. In the first Sb site, Sb(5) is bonded in a 8-coordinate geometry to one Eu(3), two equivalent Eu(2), two equivalent Eu(5), one Sb(1), one Sb(2), and one Sb(6) atom. The Sb(5)-Sb(1) bond length is 2.98 Å. The Sb(5)-Sb(2) bond length is 3.31 Å. The Sb(5)-Sb(6) bond length is 3.13 Å. In the second Sb site, Sb(6) is bonded in a 8-coordinate geometry to one Eu(2), one Eu(4), one Eu(5), two equivalent Eu(3), one Sb(3), one Sb(5), and one Sb(6) atom. The Sb(6)-Sb(3) bond length is 3.32 Å. The Sb(6)-Sb(6) bond length is 2.95 Å. In the third Sb site, Sb(1) is bonded in a 9-coordinate geometry to one Eu(1), one Eu(3), two equivalent Eu(2), two equivalent Eu(4), one Sb(3), one Sb(4), and one Sb(5) atom. The Sb(1)-Sb(3) bond length is 3.08 Å. The Sb(1)-Sb(4) bond length is 3.48 Å. In the fourth Sb site, Sb(2) is bonded in a 8-coordinate geometry to one Eu(1), one Eu(2), one Eu(4), three equivalent Eu(5), one Sb(4), and one Sb(5) atom. The Sb(2)-Sb(4) bond length is 3.10 Å. In the fifth Sb site, Sb(3) is bonded in a 8-coordinate geometry to one Eu(2), one Eu(3), one Eu(5), three equivalent Eu(4), one Sb(1), and one Sb(6) atom. In the sixth Sb site, Sb(4) is bonded in a 9-coordinate geometry to one Eu(4), one Eu(5), two equivalent Eu(1), two equivalent Eu(2), one Sb(1), one Sb(2), and one Sb(4) atom. The Sb(4)-Sb(4) bond length is 3.01 Å.