Sr(Ni5P3)2 crystallizes in the orthorhombic Cmce space group. Sr(1) is bonded in a 18-coordinate geometry to four equivalent Ni(4), six equivalent Ni(3), two equivalent P(2), two equivalent P(3), and four equivalent P(1) atoms. There are four inequivalent Ni sites. In the first Ni site, Ni(1) is bonded in a 4-coordinate geometry to two equivalent P(1) and two equivalent P(3) atoms. In the second Ni site, Ni(2) is bonded in a 4-coordinate geometry to two equivalent P(2) and two equivalent P(3) atoms. In the third Ni site, Ni(3) is bonded to three equivalent Sr(1), two equivalent P(1), and two equivalent P(2) atoms to form distorted NiSr3P4 tetrahedra that share corners with six equivalent Ni(4)SrP4 tetrahedra, corners with nine equivalent Ni(3)Sr3P4 tetrahedra, edges with four equivalent Ni(4)SrP4 tetrahedra, faces with two equivalent Ni(4)SrP4 tetrahedra, and faces with three equivalent Ni(3)Sr3P4 tetrahedra. In the fourth Ni site, Ni(4) is bonded to one Sr(1), one P(1), one P(2), and two equivalent P(3) atoms to form distorted NiSrP4 tetrahedra that share corners with three equivalent Ni(3)Sr3P4 tetrahedra, corners with five equivalent Ni(4)SrP4 tetrahedra, edges with two equivalent Ni(3)Sr3P4 tetrahedra, edges with three equivalent Ni(4)SrP4 tetrahedra, and  a faceface with one Ni(3)Sr3P4 tetrahedra. There are three inequivalent P sites. In the first P site, P(1) is bonded in a 8-coordinate geometry to two equivalent Sr(1), two equivalent Ni(1), two equivalent Ni(3), and two equivalent Ni(4) atoms. In the second P site, P(2) is bonded in a 6-coordinate geometry to one Sr(1), two equivalent Ni(2), two equivalent Ni(3), and two equivalent Ni(4) atoms. In the third P site, P(3) is bonded in a 9-coordinate geometry to one Sr(1), two equivalent Ni(1), two equivalent Ni(2), and four equivalent Ni(4) atoms.
Sr(Ni5P3)2 crystallizes in the orthorhombic Cmce space group. Sr(1) is bonded in a 18-coordinate geometry to four equivalent Ni(4), six equivalent Ni(3), two equivalent P(2), two equivalent P(3), and four equivalent P(1) atoms. All Sr(1)-Ni(4) bond lengths are 3.40 Å. There are two shorter (3.39 Å) and four longer (3.45 Å) Sr(1)-Ni(3) bond lengths. Both Sr(1)-P(2) bond lengths are 3.56 Å. Both Sr(1)-P(3) bond lengths are 3.41 Å. All Sr(1)-P(1) bond lengths are 3.20 Å. There are four inequivalent Ni sites. In the first Ni site, Ni(1) is bonded in a 4-coordinate geometry to two equivalent P(1) and two equivalent P(3) atoms. Both Ni(1)-P(1) bond lengths are 2.31 Å. There is one shorter (2.34 Å) and one longer (2.46 Å) Ni(1)-P(3) bond length. In the second Ni site, Ni(2) is bonded in a 4-coordinate geometry to two equivalent P(2) and two equivalent P(3) atoms. Both Ni(2)-P(2) bond lengths are 2.25 Å. Both Ni(2)-P(3) bond lengths are 2.34 Å. In the third Ni site, Ni(3) is bonded to three equivalent Sr(1), two equivalent P(1), and two equivalent P(2) atoms to form distorted NiSr3P4 tetrahedra that share corners with six equivalent Ni(4)SrP4 tetrahedra, corners with nine equivalent Ni(3)Sr3P4 tetrahedra, edges with four equivalent Ni(4)SrP4 tetrahedra, faces with two equivalent Ni(4)SrP4 tetrahedra, and faces with three equivalent Ni(3)Sr3P4 tetrahedra. Both Ni(3)-P(1) bond lengths are 2.21 Å. There is one shorter (2.17 Å) and one longer (2.30 Å) Ni(3)-P(2) bond length. In the fourth Ni site, Ni(4) is bonded to one Sr(1), one P(1), one P(2), and two equivalent P(3) atoms to form distorted NiSrP4 tetrahedra that share corners with three equivalent Ni(3)Sr3P4 tetrahedra, corners with five equivalent Ni(4)SrP4 tetrahedra, edges with two equivalent Ni(3)Sr3P4 tetrahedra, edges with three equivalent Ni(4)SrP4 tetrahedra, and  a faceface with one Ni(3)Sr3P4 tetrahedra. The Ni(4)-P(1) bond length is 2.23 Å. The Ni(4)-P(2) bond length is 2.31 Å. There is one shorter (2.20 Å) and one longer (2.32 Å) Ni(4)-P(3) bond length. There are three inequivalent P sites. In the first P site, P(1) is bonded in a 8-coordinate geometry to two equivalent Sr(1), two equivalent Ni(1), two equivalent Ni(3), and two equivalent Ni(4) atoms. In the second P site, P(2) is bonded in a 6-coordinate geometry to one Sr(1), two equivalent Ni(2), two equivalent Ni(3), and two equivalent Ni(4) atoms. In the third P site, P(3) is bonded in a 9-coordinate geometry to one Sr(1), two equivalent Ni(1), two equivalent Ni(2), and four equivalent Ni(4) atoms.