Nd2MnFe3Si4 crystallizes in the tetragonal P-4m2 space group. Nd(1) is bonded in a 16-coordinate geometry to two equivalent Mn(1), two equivalent Fe(1), two equivalent Fe(2), two equivalent Fe(3), four equivalent Si(1), and four equivalent Si(2) atoms. Mn(1) is bonded to four equivalent Nd(1), four equivalent Fe(2), and four equivalent Si(1) atoms to form distorted MnNd4Fe4Si4 tetrahedra that share corners with four equivalent Mn(1)Nd4Fe4Si4 tetrahedra, faces with four equivalent Fe(2)Nd4Mn4Si4 cuboctahedra, and faces with four equivalent Mn(1)Nd4Fe4Si4 tetrahedra. There are three inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in a 4-coordinate geometry to four equivalent Nd(1) and four equivalent Si(2) atoms. In the second Fe site, Fe(2) is bonded to four equivalent Nd(1), four equivalent Mn(1), and four equivalent Si(1) atoms to form distorted FeNd4Mn4Si4 cuboctahedra that share corners with four equivalent Fe(2)Nd4Mn4Si4 cuboctahedra, faces with four equivalent Fe(2)Nd4Mn4Si4 cuboctahedra, and faces with four equivalent Mn(1)Nd4Fe4Si4 tetrahedra. In the third Fe site, Fe(3) is bonded in a 4-coordinate geometry to four equivalent Nd(1) and four equivalent Si(2) atoms. 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(1), two equivalent Fe(2), 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 Fe(1), two equivalent Fe(3), and one Si(1) atom.
Nd2MnFe3Si4 crystallizes in the tetragonal P-4m2 space group. Nd(1) is bonded in a 16-coordinate geometry to two equivalent Mn(1), two equivalent Fe(1), two equivalent Fe(2), two equivalent Fe(3), four equivalent Si(1), and four equivalent Si(2) atoms. Both Nd(1)-Mn(1) bond lengths are 3.25 Å. Both Nd(1)-Fe(1) bond lengths are 3.16 Å. Both Nd(1)-Fe(2) bond lengths are 3.25 Å. Both Nd(1)-Fe(3) bond lengths are 3.16 Å. All Nd(1)-Si(1) bond lengths are 3.12 Å. All Nd(1)-Si(2) bond lengths are 3.13 Å. Mn(1) is bonded to four equivalent Nd(1), four equivalent Fe(2), and four equivalent Si(1) atoms to form distorted MnNd4Fe4Si4 tetrahedra that share corners with four equivalent Mn(1)Nd4Fe4Si4 tetrahedra, faces with four equivalent Fe(2)Nd4Mn4Si4 cuboctahedra, and faces with four equivalent Mn(1)Nd4Fe4Si4 tetrahedra. All Mn(1)-Fe(2) bond lengths are 2.83 Å. All Mn(1)-Si(1) bond lengths are 2.36 Å. There are three inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in a 4-coordinate geometry to four equivalent Nd(1) and four equivalent Si(2) atoms. All Fe(1)-Si(2) bond lengths are 2.28 Å. In the second Fe site, Fe(2) is bonded to four equivalent Nd(1), four equivalent Mn(1), and four equivalent Si(1) atoms to form distorted FeNd4Mn4Si4 cuboctahedra that share corners with four equivalent Fe(2)Nd4Mn4Si4 cuboctahedra, faces with four equivalent Fe(2)Nd4Mn4Si4 cuboctahedra, and faces with four equivalent Mn(1)Nd4Fe4Si4 tetrahedra. All Fe(2)-Si(1) bond lengths are 2.36 Å. In the third Fe site, Fe(3) is bonded in a 4-coordinate geometry to four equivalent Nd(1) and four equivalent Si(2) atoms. All Fe(3)-Si(2) bond lengths are 2.28 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(1), two equivalent Fe(2), and one Si(2) atom. The Si(1)-Si(2) bond length is 2.66 Å. In the second Si site, Si(2) is bonded in a 9-coordinate geometry to four equivalent Nd(1), two equivalent Fe(1), two equivalent Fe(3), and one Si(1) atom.