Eu2Ni7P4 crystallizes in the orthorhombic Pmn2_1 space group. There are two inequivalent Eu sites. In the first Eu site, Eu(1) is bonded in a 17-coordinate geometry to one Ni(1), one Ni(2), one Ni(6), two equivalent Ni(3), three equivalent Ni(4), three equivalent Ni(5), two equivalent P(1), two equivalent P(3), and two equivalent P(4) atoms. In the second Eu site, Eu(2) is bonded in a 16-coordinate geometry to one Ni(2), one Ni(5), two equivalent Ni(1), two equivalent Ni(3), two equivalent Ni(6), three equivalent Ni(7), two equivalent P(1), and three equivalent P(2) atoms. There are seven inequivalent Ni sites. In the first Ni site, Ni(1) is bonded in a 4-coordinate geometry to one Eu(1), two equivalent Eu(2), one P(1), one P(2), and two equivalent P(3) atoms. In the second Ni site, Ni(2) is bonded in a 3-coordinate geometry to one Eu(1), one Eu(2), one P(4), and two equivalent P(3) atoms. In the third Ni site, Ni(3) is bonded in a 4-coordinate geometry to two equivalent Eu(1), two equivalent Eu(2), one P(1), one P(4), and two equivalent P(2) atoms. In the fourth Ni site, Ni(4) is bonded in a 4-coordinate geometry to three equivalent Eu(1), one P(1), one P(3), and two equivalent P(4) atoms. In the fifth Ni site, Ni(5) is bonded to one Eu(2), three equivalent Eu(1), one P(3), one P(4), and two equivalent P(1) atoms to form a mixture of distorted edge and corner-sharing NiEu4P4 tetrahedra. In the sixth Ni site, Ni(6) is bonded in a distorted trigonal non-coplanar geometry to one Eu(1), two equivalent Eu(2), one P(2), and two equivalent P(4) atoms. In the seventh Ni site, Ni(7) is bonded in a distorted trigonal non-coplanar geometry to three equivalent Eu(2), one P(3), and two equivalent P(2) atoms. There are four inequivalent P sites. In the first P site, P(1) is bonded in a 9-coordinate geometry to two equivalent Eu(1), two equivalent Eu(2), one Ni(1), one Ni(3), one Ni(4), and two equivalent Ni(5) atoms. In the second P site, P(2) is bonded in a 9-coordinate geometry to three equivalent Eu(2), one Ni(1), one Ni(6), two equivalent Ni(3), and two equivalent Ni(7) atoms. In the third P site, P(3) is bonded in a 9-coordinate geometry to two equivalent Eu(1), one Ni(4), one Ni(5), one Ni(7), two equivalent Ni(1), and two equivalent Ni(2) atoms. In the fourth P site, P(4) is bonded in a 9-coordinate geometry to two equivalent Eu(1), one Ni(2), one Ni(3), one Ni(5), two equivalent Ni(4), and two equivalent Ni(6) atoms.
Eu2Ni7P4 crystallizes in the orthorhombic Pmn2_1 space group. There are two inequivalent Eu sites. In the first Eu site, Eu(1) is bonded in a 17-coordinate geometry to one Ni(1), one Ni(2), one Ni(6), two equivalent Ni(3), three equivalent Ni(4), three equivalent Ni(5), two equivalent P(1), two equivalent P(3), and two equivalent P(4) atoms. The Eu(1)-Ni(1) bond length is 3.28 Å. The Eu(1)-Ni(2) bond length is 3.17 Å. The Eu(1)-Ni(6) bond length is 3.15 Å. Both Eu(1)-Ni(3) bond lengths are 3.04 Å. There are two shorter (3.01 Å) and one longer (3.16 Å) Eu(1)-Ni(4) bond length. All Eu(1)-Ni(5) bond lengths are 3.16 Å. Both Eu(1)-P(1) bond lengths are 2.94 Å. Both Eu(1)-P(3) bond lengths are 2.92 Å. Both Eu(1)-P(4) bond lengths are 2.87 Å. In the second Eu site, Eu(2) is bonded in a 16-coordinate geometry to one Ni(2), one Ni(5), two equivalent Ni(1), two equivalent Ni(3), two equivalent Ni(6), three equivalent Ni(7), two equivalent P(1), and three equivalent P(2) atoms. The Eu(2)-Ni(2) bond length is 3.04 Å. The Eu(2)-Ni(5) bond length is 3.26 Å. Both Eu(2)-Ni(1) bond lengths are 3.01 Å. Both Eu(2)-Ni(3) bond lengths are 3.31 Å. Both Eu(2)-Ni(6) bond lengths are 3.13 Å. There are two shorter (3.08 Å) and one longer (3.21 Å) Eu(2)-Ni(7) bond length. Both Eu(2)-P(1) bond lengths are 3.00 Å. There is one shorter (2.97 Å) and two longer (3.06 Å) Eu(2)-P(2) bond lengths. There are seven inequivalent Ni sites. In the first Ni site, Ni(1) is bonded in a 4-coordinate geometry to one Eu(1), two equivalent Eu(2), one P(1), one P(2), and two equivalent P(3) atoms. The Ni(1)-P(1) bond length is 2.27 Å. The Ni(1)-P(2) bond length is 2.38 Å. Both Ni(1)-P(3) bond lengths are 2.38 Å. In the second Ni site, Ni(2) is bonded in a 3-coordinate geometry to one Eu(1), one Eu(2), one P(4), and two equivalent P(3) atoms. The Ni(2)-P(4) bond length is 2.16 Å. Both Ni(2)-P(3) bond lengths are 2.33 Å. In the third Ni site, Ni(3) is bonded in a 4-coordinate geometry to two equivalent Eu(1), two equivalent Eu(2), one P(1), one P(4), and two equivalent P(2) atoms. The Ni(3)-P(1) bond length is 2.48 Å. The Ni(3)-P(4) bond length is 2.32 Å. Both Ni(3)-P(2) bond lengths are 2.43 Å. In the fourth Ni site, Ni(4) is bonded in a 4-coordinate geometry to three equivalent Eu(1), one P(1), one P(3), and two equivalent P(4) atoms. The Ni(4)-P(1) bond length is 2.29 Å. The Ni(4)-P(3) bond length is 2.31 Å. Both Ni(4)-P(4) bond lengths are 2.38 Å. In the fifth Ni site, Ni(5) is bonded to one Eu(2), three equivalent Eu(1), one P(3), one P(4), and two equivalent P(1) atoms to form a mixture of distorted edge and corner-sharing NiEu4P4 tetrahedra. The Ni(5)-P(3) bond length is 2.29 Å. The Ni(5)-P(4) bond length is 2.36 Å. Both Ni(5)-P(1) bond lengths are 2.38 Å. In the sixth Ni site, Ni(6) is bonded in a distorted trigonal non-coplanar geometry to one Eu(1), two equivalent Eu(2), one P(2), and two equivalent P(4) atoms. The Ni(6)-P(2) bond length is 2.20 Å. Both Ni(6)-P(4) bond lengths are 2.34 Å. In the seventh Ni site, Ni(7) is bonded in a distorted trigonal non-coplanar geometry to three equivalent Eu(2), one P(3), and two equivalent P(2) atoms. The Ni(7)-P(3) bond length is 2.18 Å. Both Ni(7)-P(2) bond lengths are 2.30 Å. There are four inequivalent P sites. In the first P site, P(1) is bonded in a 9-coordinate geometry to two equivalent Eu(1), two equivalent Eu(2), one Ni(1), one Ni(3), one Ni(4), and two equivalent Ni(5) atoms. In the second P site, P(2) is bonded in a 9-coordinate geometry to three equivalent Eu(2), one Ni(1), one Ni(6), two equivalent Ni(3), and two equivalent Ni(7) atoms. In the third P site, P(3) is bonded in a 9-coordinate geometry to two equivalent Eu(1), one Ni(4), one Ni(5), one Ni(7), two equivalent Ni(1), and two equivalent Ni(2) atoms. In the fourth P site, P(4) is bonded in a 9-coordinate geometry to two equivalent Eu(1), one Ni(2), one Ni(3), one Ni(5), two equivalent Ni(4), and two equivalent Ni(6) atoms.