EuNi5As3 crystallizes in the orthorhombic Cmcm space group. Eu(1) is bonded in a 15-coordinate geometry to four equivalent Ni(1), four equivalent Ni(3), three equivalent As(2), and four equivalent As(1) atoms. There are three inequivalent Ni sites. In the first Ni site, Ni(1) is bonded in a 4-coordinate geometry to two equivalent Eu(1), one As(2), and three equivalent As(1) atoms. In the second Ni site, Ni(2) is bonded in a 4-coordinate geometry to four equivalent As(1) atoms. In the third Ni site, Ni(3) is bonded in a 4-coordinate geometry to two equivalent Eu(1), two equivalent As(1), and two equivalent As(2) atoms. There are two inequivalent As sites. In the first As site, As(1) is bonded in a 9-coordinate geometry to two equivalent Eu(1), two equivalent Ni(2), two equivalent Ni(3), and three equivalent Ni(1) atoms. In the second As site, As(2) is bonded in a 6-coordinate geometry to three equivalent Eu(1), two equivalent Ni(1), and four equivalent Ni(3) atoms.
EuNi5As3 crystallizes in the orthorhombic Cmcm space group. Eu(1) is bonded in a 15-coordinate geometry to four equivalent Ni(1), four equivalent Ni(3), three equivalent As(2), and four equivalent As(1) atoms. All Eu(1)-Ni(1) bond lengths are 3.33 Å. All Eu(1)-Ni(3) bond lengths are 3.40 Å. There are two shorter (3.26 Å) and one longer (3.37 Å) Eu(1)-As(2) bond length. All Eu(1)-As(1) bond lengths are 3.10 Å. There are three inequivalent Ni sites. In the first Ni site, Ni(1) is bonded in a 4-coordinate geometry to two equivalent Eu(1), one As(2), and three equivalent As(1) atoms. The Ni(1)-As(2) bond length is 2.36 Å. There is one shorter (2.26 Å) and two longer (2.42 Å) Ni(1)-As(1) bond lengths. In the second Ni site, Ni(2) is bonded in a 4-coordinate geometry to four equivalent As(1) atoms. All Ni(2)-As(1) bond lengths are 2.42 Å. In the third Ni site, Ni(3) is bonded in a 4-coordinate geometry to two equivalent Eu(1), two equivalent As(1), and two equivalent As(2) atoms. There is one shorter (2.37 Å) and one longer (2.38 Å) Ni(3)-As(1) bond length. Both Ni(3)-As(2) bond lengths are 2.37 Å. There are two inequivalent As sites. In the first As site, As(1) is bonded in a 9-coordinate geometry to two equivalent Eu(1), two equivalent Ni(2), two equivalent Ni(3), and three equivalent Ni(1) atoms. In the second As site, As(2) is bonded in a 6-coordinate geometry to three equivalent Eu(1), two equivalent Ni(1), and four equivalent Ni(3) atoms.