Nd6Fe13Si is Hexagonal Laves-derived structured and crystallizes in the tetragonal I4/mcm space group. There are two inequivalent Nd sites. In the first Nd site, Nd(1) is bonded in a 6-coordinate geometry to one Fe(4), three equivalent Fe(2), and two equivalent Si(1) atoms. In the second Nd site, Nd(2) is bonded in a 13-coordinate geometry to four equivalent Fe(2), four equivalent Fe(3), four equivalent Fe(4), and one Si(1) atom. There are four inequivalent Fe sites. In the first Fe site, Fe(3) is bonded to two equivalent Nd(2), one Fe(1), two equivalent Fe(2), three equivalent Fe(3), and four equivalent Fe(4) atoms to form FeNd2Fe10 cuboctahedra that share  a cornercorner with one Fe(1)Fe12 cuboctahedra, corners with three equivalent Fe(3)Nd2Fe10 cuboctahedra, corners with four equivalent Fe(2)Nd5Fe7 cuboctahedra, faces with two equivalent Fe(1)Fe12 cuboctahedra, faces with seven equivalent Fe(3)Nd2Fe10 cuboctahedra, and faces with eight equivalent Fe(2)Nd5Fe7 cuboctahedra. In the second Fe site, Fe(4) is bonded in a 12-coordinate geometry to one Nd(1), two equivalent Nd(2), one Fe(1), one Fe(4), three equivalent Fe(2), and four equivalent Fe(3) atoms. In the third Fe site, Fe(1) is bonded to four equivalent Fe(2), four equivalent Fe(3), and four equivalent Fe(4) atoms to form FeFe12 cuboctahedra that share corners with four equivalent Fe(3)Nd2Fe10 cuboctahedra, corners with four equivalent Fe(2)Nd5Fe7 cuboctahedra, faces with four equivalent Fe(2)Nd5Fe7 cuboctahedra, and faces with eight equivalent Fe(3)Nd2Fe10 cuboctahedra. In the fourth Fe site, Fe(2) is bonded to two equivalent Nd(2), three equivalent Nd(1), one Fe(1), one Fe(2), two equivalent Fe(3), and three equivalent Fe(4) atoms to form distorted FeNd5Fe7 cuboctahedra that share  a cornercorner with one Fe(1)Fe12 cuboctahedra, corners with three equivalent Fe(2)Nd5Fe7 cuboctahedra, corners with four equivalent Fe(3)Nd2Fe10 cuboctahedra,  a faceface with one Fe(1)Fe12 cuboctahedra, faces with six equivalent Fe(2)Nd5Fe7 cuboctahedra, and faces with eight equivalent Fe(3)Nd2Fe10 cuboctahedra. Si(1) is bonded in a distorted q6 geometry to two equivalent Nd(2) and eight equivalent Nd(1) atoms.
Nd6Fe13Si is Hexagonal Laves-derived structured and crystallizes in the tetragonal I4/mcm space group. There are two inequivalent Nd sites. In the first Nd site, Nd(1) is bonded in a 6-coordinate geometry to one Fe(4), three equivalent Fe(2), and two equivalent Si(1) atoms. The Nd(1)-Fe(4) bond length is 2.97 Å. There are two shorter (3.13 Å) and one longer (3.30 Å) Nd(1)-Fe(2) bond length. Both Nd(1)-Si(1) bond lengths are 3.31 Å. In the second Nd site, Nd(2) is bonded in a 13-coordinate geometry to four equivalent Fe(2), four equivalent Fe(3), four equivalent Fe(4), and one Si(1) atom. All Nd(2)-Fe(2) bond lengths are 3.25 Å. All Nd(2)-Fe(3) bond lengths are 3.06 Å. All Nd(2)-Fe(4) bond lengths are 3.15 Å. The Nd(2)-Si(1) bond length is 3.25 Å. There are four inequivalent Fe sites. In the first Fe site, Fe(3) is bonded to two equivalent Nd(2), one Fe(1), two equivalent Fe(2), three equivalent Fe(3), and four equivalent Fe(4) atoms to form FeNd2Fe10 cuboctahedra that share  a cornercorner with one Fe(1)Fe12 cuboctahedra, corners with three equivalent Fe(3)Nd2Fe10 cuboctahedra, corners with four equivalent Fe(2)Nd5Fe7 cuboctahedra, faces with two equivalent Fe(1)Fe12 cuboctahedra, faces with seven equivalent Fe(3)Nd2Fe10 cuboctahedra, and faces with eight equivalent Fe(2)Nd5Fe7 cuboctahedra. The Fe(3)-Fe(1) bond length is 2.39 Å. Both Fe(3)-Fe(2) bond lengths are 2.65 Å. There are two shorter (2.49 Å) and one longer (2.55 Å) Fe(3)-Fe(3) bond length. There are two shorter (2.48 Å) and two longer (2.57 Å) Fe(3)-Fe(4) bond lengths. In the second Fe site, Fe(4) is bonded in a 12-coordinate geometry to one Nd(1), two equivalent Nd(2), one Fe(1), one Fe(4), three equivalent Fe(2), and four equivalent Fe(3) atoms. The Fe(4)-Fe(1) bond length is 2.46 Å. The Fe(4)-Fe(4) bond length is 2.76 Å. There is one shorter (2.49 Å) and two longer (2.54 Å) Fe(4)-Fe(2) bond lengths. In the third Fe site, Fe(1) is bonded to four equivalent Fe(2), four equivalent Fe(3), and four equivalent Fe(4) atoms to form FeFe12 cuboctahedra that share corners with four equivalent Fe(3)Nd2Fe10 cuboctahedra, corners with four equivalent Fe(2)Nd5Fe7 cuboctahedra, faces with four equivalent Fe(2)Nd5Fe7 cuboctahedra, and faces with eight equivalent Fe(3)Nd2Fe10 cuboctahedra. All Fe(1)-Fe(2) bond lengths are 2.55 Å. In the fourth Fe site, Fe(2) is bonded to two equivalent Nd(2), three equivalent Nd(1), one Fe(1), one Fe(2), two equivalent Fe(3), and three equivalent Fe(4) atoms to form distorted FeNd5Fe7 cuboctahedra that share  a cornercorner with one Fe(1)Fe12 cuboctahedra, corners with three equivalent Fe(2)Nd5Fe7 cuboctahedra, corners with four equivalent Fe(3)Nd2Fe10 cuboctahedra,  a faceface with one Fe(1)Fe12 cuboctahedra, faces with six equivalent Fe(2)Nd5Fe7 cuboctahedra, and faces with eight equivalent Fe(3)Nd2Fe10 cuboctahedra. The Fe(2)-Fe(2) bond length is 2.57 Å. Si(1) is bonded in a distorted q6 geometry to two equivalent Nd(2) and eight equivalent Nd(1) atoms.