NdS3 crystallizes in the hexagonal P6_3/mmc space group. The structure is three-dimensional. Nd2+ is bonded to twelve equivalent S+0.67- atoms to form a mixture of distorted corner and face-sharing NdS12 cuboctahedra. There are six shorter (2.88 Å) and six longer (3.24 Å) Nd–S bond lengths. S+0.67- is bonded in a 2-coordinate geometry to four equivalent Nd2+ atoms.