Eu2Ni8Si3 crystallizes in the tetragonal P4_2/nmc space group. Eu(1) is bonded in a 13-coordinate geometry to one Ni(3), three equivalent Ni(2), six equivalent Ni(1), one Si(2), and two equivalent Si(1) atoms. There are three inequivalent Ni sites. In the first Ni site, Ni(1) is bonded in a 10-coordinate geometry to three equivalent Eu(1), one Ni(3), two equivalent Ni(1), two equivalent Ni(2), and two equivalent Si(1) atoms. In the second Ni site, Ni(2) is bonded in a 11-coordinate geometry to three equivalent Eu(1), one Ni(2), one Ni(3), four equivalent Ni(1), and two equivalent Si(1) atoms. In the third Ni site, Ni(3) is bonded in a 10-coordinate geometry to one Eu(1), one Ni(2), two equivalent Ni(1), two equivalent Ni(3), two equivalent Si(1), and two equivalent Si(2) atoms. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded in a 6-coordinate geometry to two equivalent Eu(1), two equivalent Ni(2), two equivalent Ni(3), and four equivalent Ni(1) atoms. In the second Si site, Si(2) is bonded in a 6-coordinate geometry to two equivalent Eu(1) and four equivalent Ni(3) atoms.
Eu2Ni8Si3 crystallizes in the tetragonal P4_2/nmc space group. Eu(1) is bonded in a 13-coordinate geometry to one Ni(3), three equivalent Ni(2), six equivalent Ni(1), one Si(2), and two equivalent Si(1) atoms. The Eu(1)-Ni(3) bond length is 3.07 Å. There is one shorter (2.92 Å) and two longer (2.95 Å) Eu(1)-Ni(2) bond lengths. There are a spread of Eu(1)-Ni(1) bond distances ranging from 2.79-3.27 Å. The Eu(1)-Si(2) bond length is 2.83 Å. Both Eu(1)-Si(1) bond lengths are 3.09 Å. There are three inequivalent Ni sites. In the first Ni site, Ni(1) is bonded in a 10-coordinate geometry to three equivalent Eu(1), one Ni(3), two equivalent Ni(1), two equivalent Ni(2), and two equivalent Si(1) atoms. The Ni(1)-Ni(3) bond length is 2.47 Å. There is one shorter (2.50 Å) and one longer (2.76 Å) Ni(1)-Ni(1) bond length. There is one shorter (2.62 Å) and one longer (2.77 Å) Ni(1)-Ni(2) bond length. There is one shorter (2.32 Å) and one longer (2.33 Å) Ni(1)-Si(1) bond length. In the second Ni site, Ni(2) is bonded in a 11-coordinate geometry to three equivalent Eu(1), one Ni(2), one Ni(3), four equivalent Ni(1), and two equivalent Si(1) atoms. The Ni(2)-Ni(2) bond length is 2.37 Å. The Ni(2)-Ni(3) bond length is 2.34 Å. Both Ni(2)-Si(1) bond lengths are 2.83 Å. In the third Ni site, Ni(3) is bonded in a 10-coordinate geometry to one Eu(1), one Ni(2), two equivalent Ni(1), two equivalent Ni(3), two equivalent Si(1), and two equivalent Si(2) atoms. Both Ni(3)-Ni(3) bond lengths are 2.39 Å. Both Ni(3)-Si(1) bond lengths are 2.33 Å. There is one shorter (2.18 Å) and one longer (2.55 Å) Ni(3)-Si(2) bond length. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded in a 6-coordinate geometry to two equivalent Eu(1), two equivalent Ni(2), two equivalent Ni(3), and four equivalent Ni(1) atoms. In the second Si site, Si(2) is bonded in a 6-coordinate geometry to two equivalent Eu(1) and four equivalent Ni(3) atoms.