NdCo9Si2 crystallizes in the tetragonal I4_1/amd space group. Nd(1) is bonded in a 18-coordinate geometry to two equivalent Co(1) and sixteen equivalent Co(2) atoms. There are two inequivalent Co sites. In the first Co site, Co(1) is bonded in a 14-coordinate geometry to two equivalent Nd(1), eight equivalent Co(2), and four equivalent Si(1) atoms. In the second Co site, Co(2) is bonded in a 12-coordinate geometry to two equivalent Nd(1), one Co(1), seven equivalent Co(2), and two equivalent Si(1) atoms. Si(1) is bonded in a 10-coordinate geometry to two equivalent Co(1) and eight equivalent Co(2) atoms.
NdCo9Si2 crystallizes in the tetragonal I4_1/amd space group. Nd(1) is bonded in a 18-coordinate geometry to two equivalent Co(1) and sixteen equivalent Co(2) atoms. Both Nd(1)-Co(1) bond lengths are 3.13 Å. There are eight shorter (3.03 Å) and eight longer (3.11 Å) Nd(1)-Co(2) bond lengths. There are two inequivalent Co sites. In the first Co site, Co(1) is bonded in a 14-coordinate geometry to two equivalent Nd(1), eight equivalent Co(2), and four equivalent Si(1) atoms. All Co(1)-Co(2) bond lengths are 2.63 Å. All Co(1)-Si(1) bond lengths are 2.54 Å. In the second Co site, Co(2) is bonded in a 12-coordinate geometry to two equivalent Nd(1), one Co(1), seven equivalent Co(2), and two equivalent Si(1) atoms. There are a spread of Co(2)-Co(2) bond distances ranging from 2.39-2.64 Å. There is one shorter (2.36 Å) and one longer (2.37 Å) Co(2)-Si(1) bond length. Si(1) is bonded in a 10-coordinate geometry to two equivalent Co(1) and eight equivalent Co(2) atoms.