EuNiGe3 crystallizes in the tetragonal I4mm space group. Eu(1) is bonded in a 17-coordinate geometry to five equivalent Ni(1), four equivalent Ge(2), and eight equivalent Ge(1) atoms. Ni(1) is bonded in a 5-coordinate geometry to five equivalent Eu(1), one Ge(2), and four equivalent Ge(1) atoms. There are two inequivalent Ge sites. In the first Ge site, Ge(1) is bonded in a 8-coordinate geometry to four equivalent Eu(1), two equivalent Ni(1), and two equivalent Ge(2) atoms. In the second Ge site, Ge(2) is bonded in a 9-coordinate geometry to four equivalent Eu(1), one Ni(1), and four equivalent Ge(1) atoms.
EuNiGe3 crystallizes in the tetragonal I4mm space group. Eu(1) is bonded in a 17-coordinate geometry to five equivalent Ni(1), four equivalent Ge(2), and eight equivalent Ge(1) atoms. There is one shorter (3.38 Å) and four longer (3.42 Å) Eu(1)-Ni(1) bond lengths. All Eu(1)-Ge(2) bond lengths are 3.17 Å. There are four shorter (3.24 Å) and four longer (3.30 Å) Eu(1)-Ge(1) bond lengths. Ni(1) is bonded in a 5-coordinate geometry to five equivalent Eu(1), one Ge(2), and four equivalent Ge(1) atoms. The Ni(1)-Ge(2) bond length is 2.33 Å. All Ni(1)-Ge(1) bond lengths are 2.37 Å. There are two inequivalent Ge sites. In the first Ge site, Ge(1) is bonded in a 8-coordinate geometry to four equivalent Eu(1), two equivalent Ni(1), and two equivalent Ge(2) atoms. Both Ge(1)-Ge(2) bond lengths are 2.70 Å. In the second Ge site, Ge(2) is bonded in a 9-coordinate geometry to four equivalent Eu(1), one Ni(1), and four equivalent Ge(1) atoms.