Nd4Si7 crystallizes in the orthorhombic Pmm2 space group. There are four inequivalent Nd sites. In the first Nd site, Nd(1) is bonded in a 8-coordinate geometry to two equivalent Si(3), two equivalent Si(7), and four equivalent Si(1) atoms. In the second Nd site, Nd(2) is bonded to two equivalent Si(4), two equivalent Si(6), four equivalent Si(2), and four equivalent Si(5) atoms to form a mixture of edge and face-sharing NdSi12 cuboctahedra. In the third Nd site, Nd(3) is bonded to two equivalent Si(1), two equivalent Si(5), four equivalent Si(3), and four equivalent Si(6) atoms to form a mixture of edge and face-sharing NdSi12 cuboctahedra. In the fourth Nd site, Nd(4) is bonded in a 10-coordinate geometry to two equivalent Si(2), four equivalent Si(4), and four equivalent Si(7) atoms. There are seven inequivalent Si sites. In the first Si site, Si(1) is bonded in a 8-coordinate geometry to two equivalent Nd(3), four equivalent Nd(1), and two equivalent Si(3) atoms. In the second Si site, Si(2) is bonded in a 9-coordinate geometry to two equivalent Nd(4), four equivalent Nd(2), one Si(5), and two equivalent Si(4) atoms. In the third Si site, Si(3) is bonded in a 9-coordinate geometry to two equivalent Nd(1), four equivalent Nd(3), one Si(6), and two equivalent Si(1) atoms. In the fourth Si site, Si(4) is bonded in a 9-coordinate geometry to two equivalent Nd(2), four equivalent Nd(4), one Si(7), and two equivalent Si(2) atoms. In the fifth Si site, Si(5) is bonded in a 9-coordinate geometry to two equivalent Nd(3), four equivalent Nd(2), one Si(2), and two equivalent Si(6) atoms. In the sixth Si site, Si(6) is bonded in a 9-coordinate geometry to two equivalent Nd(2), four equivalent Nd(3), one Si(3), and two equivalent Si(5) atoms. In the seventh Si site, Si(7) is bonded in a 7-coordinate geometry to two equivalent Nd(1), four equivalent Nd(4), and one Si(4) atom.
Nd4Si7 crystallizes in the orthorhombic Pmm2 space group. There are four inequivalent Nd sites. In the first Nd site, Nd(1) is bonded in a 8-coordinate geometry to two equivalent Si(3), two equivalent Si(7), and four equivalent Si(1) atoms. Both Nd(1)-Si(3) bond lengths are 3.10 Å. Both Nd(1)-Si(7) bond lengths are 3.06 Å. All Nd(1)-Si(1) bond lengths are 3.11 Å. In the second Nd site, Nd(2) is bonded to two equivalent Si(4), two equivalent Si(6), four equivalent Si(2), and four equivalent Si(5) atoms to form a mixture of edge and face-sharing NdSi12 cuboctahedra. Both Nd(2)-Si(4) bond lengths are 3.17 Å. Both Nd(2)-Si(6) bond lengths are 3.07 Å. All Nd(2)-Si(2) bond lengths are 3.17 Å. All Nd(2)-Si(5) bond lengths are 3.18 Å. In the third Nd site, Nd(3) is bonded to two equivalent Si(1), two equivalent Si(5), four equivalent Si(3), and four equivalent Si(6) atoms to form a mixture of edge and face-sharing NdSi12 cuboctahedra. Both Nd(3)-Si(1) bond lengths are 3.25 Å. Both Nd(3)-Si(5) bond lengths are 3.08 Å. All Nd(3)-Si(3) bond lengths are 3.18 Å. All Nd(3)-Si(6) bond lengths are 3.18 Å. In the fourth Nd site, Nd(4) is bonded in a 10-coordinate geometry to two equivalent Si(2), four equivalent Si(4), and four equivalent Si(7) atoms. Both Nd(4)-Si(2) bond lengths are 3.10 Å. All Nd(4)-Si(4) bond lengths are 3.14 Å. All Nd(4)-Si(7) bond lengths are 3.19 Å. There are seven inequivalent Si sites. In the first Si site, Si(1) is bonded in a 8-coordinate geometry to two equivalent Nd(3), four equivalent Nd(1), and two equivalent Si(3) atoms. Both Si(1)-Si(3) bond lengths are 2.41 Å. In the second Si site, Si(2) is bonded in a 9-coordinate geometry to two equivalent Nd(4), four equivalent Nd(2), one Si(5), and two equivalent Si(4) atoms. The Si(2)-Si(5) bond length is 2.35 Å. Both Si(2)-Si(4) bond lengths are 2.37 Å. In the third Si site, Si(3) is bonded in a 9-coordinate geometry to two equivalent Nd(1), four equivalent Nd(3), one Si(6), and two equivalent Si(1) atoms. The Si(3)-Si(6) bond length is 2.37 Å. In the fourth Si site, Si(4) is bonded in a 9-coordinate geometry to two equivalent Nd(2), four equivalent Nd(4), one Si(7), and two equivalent Si(2) atoms. The Si(4)-Si(7) bond length is 2.30 Å. In the fifth Si site, Si(5) is bonded in a 9-coordinate geometry to two equivalent Nd(3), four equivalent Nd(2), one Si(2), and two equivalent Si(6) atoms. Both Si(5)-Si(6) bond lengths are 2.39 Å. In the sixth Si site, Si(6) is bonded in a 9-coordinate geometry to two equivalent Nd(2), four equivalent Nd(3), one Si(3), and two equivalent Si(5) atoms. In the seventh Si site, Si(7) is bonded in a 7-coordinate geometry to two equivalent Nd(1), four equivalent Nd(4), and one Si(4) atom.