Nd2Mn3FeSi4 crystallizes in the tetragonal P-4m2 space group. Nd(1) is bonded in a 16-coordinate geometry to two equivalent Mn(1), two equivalent Mn(2), two equivalent Mn(3), two equivalent Fe(1), four equivalent Si(1), and four equivalent Si(2) atoms. There are three inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to four equivalent Nd(1) and four equivalent Si(2) atoms to form MnNd4Si4 tetrahedra that share corners with eight equivalent Fe(1)Nd4Mn4Si4 cuboctahedra, corners with four equivalent Mn(2)Nd4Fe4Si4 tetrahedra, edges with two equivalent Mn(2)Nd4Fe4Si4 tetrahedra, edges with four equivalent Mn(1)Nd4Si4 tetrahedra, and faces with four equivalent Mn(3)Nd4Si4 tetrahedra. In the second Mn site, Mn(2) is bonded to four equivalent Nd(1), four equivalent Fe(1), and four equivalent Si(1) atoms to form distorted MnNd4Fe4Si4 tetrahedra that share corners with four equivalent Mn(2)Nd4Fe4Si4 tetrahedra, corners with four equivalent Mn(1)Nd4Si4 tetrahedra, corners with eight equivalent Mn(3)Nd4Si4 tetrahedra, edges with two equivalent Mn(1)Nd4Si4 tetrahedra, faces with four equivalent Fe(1)Nd4Mn4Si4 cuboctahedra, and faces with four equivalent Mn(2)Nd4Fe4Si4 tetrahedra. In the third Mn site, Mn(3) is bonded to four equivalent Nd(1) and four equivalent Si(2) atoms to form MnNd4Si4 tetrahedra that share corners with four equivalent Fe(1)Nd4Mn4Si4 cuboctahedra, corners with eight equivalent Mn(2)Nd4Fe4Si4 tetrahedra, edges with two equivalent Fe(1)Nd4Mn4Si4 cuboctahedra, edges with four equivalent Mn(3)Nd4Si4 tetrahedra, and faces with four equivalent Mn(1)Nd4Si4 tetrahedra. Fe(1) is bonded to four equivalent Nd(1), four equivalent Mn(2), and four equivalent Si(1) atoms to form distorted FeNd4Mn4Si4 cuboctahedra that share corners with four equivalent Fe(1)Nd4Mn4Si4 cuboctahedra, corners with four equivalent Mn(3)Nd4Si4 tetrahedra, corners with eight equivalent Mn(1)Nd4Si4 tetrahedra, edges with two equivalent Mn(3)Nd4Si4 tetrahedra, faces with four equivalent Fe(1)Nd4Mn4Si4 cuboctahedra, and faces with four equivalent Mn(2)Nd4Fe4Si4 tetrahedra. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded in a 9-coordinate geometry to four equivalent Nd(1), two equivalent Mn(2), two equivalent Fe(1), and one Si(2) atom. In the second Si site, Si(2) is bonded in a 9-coordinate geometry to four equivalent Nd(1), two equivalent Mn(1), two equivalent Mn(3), and one Si(1) atom.
Nd2Mn3FeSi4 crystallizes in the tetragonal P-4m2 space group. Nd(1) is bonded in a 16-coordinate geometry to two equivalent Mn(1), two equivalent Mn(2), two equivalent Mn(3), two equivalent Fe(1), four equivalent Si(1), and four equivalent Si(2) atoms. Both Nd(1)-Mn(1) bond lengths are 3.29 Å. Both Nd(1)-Mn(2) bond lengths are 3.27 Å. Both Nd(1)-Mn(3) bond lengths are 3.29 Å. Both Nd(1)-Fe(1) bond lengths are 3.27 Å. All Nd(1)-Si(1) bond lengths are 3.10 Å. All Nd(1)-Si(2) bond lengths are 3.09 Å. There are three inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to four equivalent Nd(1) and four equivalent Si(2) atoms to form MnNd4Si4 tetrahedra that share corners with eight equivalent Fe(1)Nd4Mn4Si4 cuboctahedra, corners with four equivalent Mn(2)Nd4Fe4Si4 tetrahedra, edges with two equivalent Mn(2)Nd4Fe4Si4 tetrahedra, edges with four equivalent Mn(1)Nd4Si4 tetrahedra, and faces with four equivalent Mn(3)Nd4Si4 tetrahedra. All Mn(1)-Si(2) bond lengths are 2.37 Å. In the second Mn site, Mn(2) is bonded to four equivalent Nd(1), four equivalent Fe(1), and four equivalent Si(1) atoms to form distorted MnNd4Fe4Si4 tetrahedra that share corners with four equivalent Mn(2)Nd4Fe4Si4 tetrahedra, corners with four equivalent Mn(1)Nd4Si4 tetrahedra, corners with eight equivalent Mn(3)Nd4Si4 tetrahedra, edges with two equivalent Mn(1)Nd4Si4 tetrahedra, faces with four equivalent Fe(1)Nd4Mn4Si4 cuboctahedra, and faces with four equivalent Mn(2)Nd4Fe4Si4 tetrahedra. All Mn(2)-Fe(1) bond lengths are 2.80 Å. All Mn(2)-Si(1) bond lengths are 2.35 Å. In the third Mn site, Mn(3) is bonded to four equivalent Nd(1) and four equivalent Si(2) atoms to form MnNd4Si4 tetrahedra that share corners with four equivalent Fe(1)Nd4Mn4Si4 cuboctahedra, corners with eight equivalent Mn(2)Nd4Fe4Si4 tetrahedra, edges with two equivalent Fe(1)Nd4Mn4Si4 cuboctahedra, edges with four equivalent Mn(3)Nd4Si4 tetrahedra, and faces with four equivalent Mn(1)Nd4Si4 tetrahedra. All Mn(3)-Si(2) bond lengths are 2.37 Å. Fe(1) is bonded to four equivalent Nd(1), four equivalent Mn(2), and four equivalent Si(1) atoms to form distorted FeNd4Mn4Si4 cuboctahedra that share corners with four equivalent Fe(1)Nd4Mn4Si4 cuboctahedra, corners with four equivalent Mn(3)Nd4Si4 tetrahedra, corners with eight equivalent Mn(1)Nd4Si4 tetrahedra, edges with two equivalent Mn(3)Nd4Si4 tetrahedra, faces with four equivalent Fe(1)Nd4Mn4Si4 cuboctahedra, and faces with four equivalent Mn(2)Nd4Fe4Si4 tetrahedra. All Fe(1)-Si(1) bond lengths are 2.35 Å. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded in a 9-coordinate geometry to four equivalent Nd(1), two equivalent Mn(2), two equivalent Fe(1), and one Si(2) atom. The Si(1)-Si(2) bond length is 2.64 Å. In the second Si site, Si(2) is bonded in a 9-coordinate geometry to four equivalent Nd(1), two equivalent Mn(1), two equivalent Mn(3), and one Si(1) atom.