Nd3Sn7 crystallizes in the orthorhombic Cmmm space group. There are two inequivalent Nd sites. In the first Nd site, Nd(1) is bonded in a 10-coordinate geometry to two equivalent Sn(1), two equivalent Sn(3), and six equivalent Sn(2) atoms. In the second Nd site, Nd(2) is bonded to four equivalent Sn(1), four equivalent Sn(3), and four equivalent Sn(4) atoms to form a mixture of corner and face-sharing NdSn12 cuboctahedra. There are four inequivalent Sn sites. In the first Sn site, Sn(1) is bonded in a 10-coordinate geometry to two equivalent Nd(1), two equivalent Nd(2), two equivalent Sn(4), and four equivalent Sn(3) atoms. In the second Sn site, Sn(2) is bonded in a 8-coordinate geometry to six equivalent Nd(1) and two equivalent Sn(2) atoms. In the third Sn site, Sn(3) is bonded in a 4-coordinate geometry to two equivalent Nd(1), two equivalent Nd(2), and four equivalent Sn(1) atoms. In the fourth Sn site, Sn(4) is bonded in a square co-planar geometry to four equivalent Nd(2) and four equivalent Sn(1) atoms.
Nd3Sn7 crystallizes in the orthorhombic Cmmm space group. There are two inequivalent Nd sites. In the first Nd site, Nd(1) is bonded in a 10-coordinate geometry to two equivalent Sn(1), two equivalent Sn(3), and six equivalent Sn(2) atoms. Both Nd(1)-Sn(1) bond lengths are 3.30 Å. Both Nd(1)-Sn(3) bond lengths are 3.28 Å. There are four shorter (3.31 Å) and two longer (3.56 Å) Nd(1)-Sn(2) bond lengths. In the second Nd site, Nd(2) is bonded to four equivalent Sn(1), four equivalent Sn(3), and four equivalent Sn(4) atoms to form a mixture of corner and face-sharing NdSn12 cuboctahedra. All Nd(2)-Sn(1) bond lengths are 3.43 Å. All Nd(2)-Sn(3) bond lengths are 3.38 Å. All Nd(2)-Sn(4) bond lengths are 3.22 Å. There are four inequivalent Sn sites. In the first Sn site, Sn(1) is bonded in a 10-coordinate geometry to two equivalent Nd(1), two equivalent Nd(2), two equivalent Sn(4), and four equivalent Sn(3) atoms. Both Sn(1)-Sn(4) bond lengths are 3.40 Å. All Sn(1)-Sn(3) bond lengths are 3.22 Å. In the second Sn site, Sn(2) is bonded in a 8-coordinate geometry to six equivalent Nd(1) and two equivalent Sn(2) atoms. Both Sn(2)-Sn(2) bond lengths are 2.98 Å. In the third Sn site, Sn(3) is bonded in a 4-coordinate geometry to two equivalent Nd(1), two equivalent Nd(2), and four equivalent Sn(1) atoms. In the fourth Sn site, Sn(4) is bonded in a square co-planar geometry to four equivalent Nd(2) and four equivalent Sn(1) atoms.