Th2NiC2 crystallizes in the tetragonal I4/mmm space group. Th(1) is bonded to five equivalent C(1) atoms to form a mixture of distorted edge and corner-sharing ThC5 square pyramids. Ni(1) is bonded in a linear geometry to two equivalent C(1) atoms. C(1) is bonded to five equivalent Th(1) and one Ni(1) atom to form a mixture of edge and corner-sharing CTh5Ni octahedra. The corner-sharing octahedral tilt angles range from 0-5°.
Th2NiC2 crystallizes in the tetragonal I4/mmm space group. Th(1) is bonded to five equivalent C(1) atoms to form a mixture of distorted edge and corner-sharing ThC5 square pyramids. There is one shorter (2.43 Å) and four longer (2.67 Å) Th(1)-C(1) bond lengths. Ni(1) is bonded in a linear geometry to two equivalent C(1) atoms. Both Ni(1)-C(1) bond lengths are 1.91 Å. C(1) is bonded to five equivalent Th(1) and one Ni(1) atom to form a mixture of edge and corner-sharing CTh5Ni octahedra. The corner-sharing octahedral tilt angles range from 0-5°.