Mn3NiP2 crystallizes in the orthorhombic Pmc2_1 space group. There are three inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to two equivalent Ni(1), two equivalent P(1), and two equivalent P(2) atoms to form a mixture of distorted corner and edge-sharing MnNi2P4 tetrahedra. In the second Mn site, Mn(2) is bonded in a 5-coordinate geometry to two equivalent Ni(1), one P(1), and four equivalent P(2) atoms. In the third Mn site, Mn(3) is bonded in a 5-coordinate geometry to four equivalent Ni(1), one P(2), and four equivalent P(1) atoms. Ni(1) is bonded in a 12-coordinate geometry to two equivalent Mn(1), two equivalent Mn(2), four equivalent Mn(3), two equivalent P(1), and two equivalent P(2) atoms. There are two inequivalent P sites. In the first P site, P(1) is bonded in a 9-coordinate geometry to one Mn(2), two equivalent Mn(1), four equivalent Mn(3), and two equivalent Ni(1) atoms. In the second P site, P(2) is bonded in a 9-coordinate geometry to one Mn(3), two equivalent Mn(1), four equivalent Mn(2), and two equivalent Ni(1) atoms.
Mn3NiP2 crystallizes in the orthorhombic Pmc2_1 space group. There are three inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to two equivalent Ni(1), two equivalent P(1), and two equivalent P(2) atoms to form a mixture of distorted corner and edge-sharing MnNi2P4 tetrahedra. Both Mn(1)-Ni(1) bond lengths are 2.66 Å. Both Mn(1)-P(1) bond lengths are 2.32 Å. There is one shorter (2.28 Å) and one longer (2.34 Å) Mn(1)-P(2) bond length. In the second Mn site, Mn(2) is bonded in a 5-coordinate geometry to two equivalent Ni(1), one P(1), and four equivalent P(2) atoms. There is one shorter (2.83 Å) and one longer (2.85 Å) Mn(2)-Ni(1) bond length. The Mn(2)-P(1) bond length is 2.51 Å. There are two shorter (2.54 Å) and two longer (2.65 Å) Mn(2)-P(2) bond lengths. In the third Mn site, Mn(3) is bonded in a 5-coordinate geometry to four equivalent Ni(1), one P(2), and four equivalent P(1) atoms. There are two shorter (2.77 Å) and two longer (2.79 Å) Mn(3)-Ni(1) bond lengths. The Mn(3)-P(2) bond length is 2.47 Å. There are two shorter (2.56 Å) and two longer (2.60 Å) Mn(3)-P(1) bond lengths. Ni(1) is bonded in a 12-coordinate geometry to two equivalent Mn(1), two equivalent Mn(2), four equivalent Mn(3), two equivalent P(1), and two equivalent P(2) atoms. There is one shorter (2.25 Å) and one longer (2.35 Å) Ni(1)-P(1) bond length. Both Ni(1)-P(2) bond lengths are 2.29 Å. There are two inequivalent P sites. In the first P site, P(1) is bonded in a 9-coordinate geometry to one Mn(2), two equivalent Mn(1), four equivalent Mn(3), and two equivalent Ni(1) atoms. In the second P site, P(2) is bonded in a 9-coordinate geometry to one Mn(3), two equivalent Mn(1), four equivalent Mn(2), and two equivalent Ni(1) atoms.