Np(CoGe)2 crystallizes in the tetragonal I4/mmm space group. Np(1) is bonded in a 16-coordinate geometry to eight equivalent Co(1) and eight equivalent Ge(1) atoms. Co(1) is bonded to four equivalent Np(1) and four equivalent Ge(1) atoms to form a mixture of distorted edge, corner, and face-sharing CoNp4Ge4 tetrahedra. Ge(1) is bonded in a 9-coordinate geometry to four equivalent Np(1), four equivalent Co(1), and one Ge(1) atom.
Np(CoGe)2 crystallizes in the tetragonal I4/mmm space group. Np(1) is bonded in a 16-coordinate geometry to eight equivalent Co(1) and eight equivalent Ge(1) atoms. All Np(1)-Co(1) bond lengths are 3.20 Å. All Np(1)-Ge(1) bond lengths are 3.08 Å. Co(1) is bonded to four equivalent Np(1) and four equivalent Ge(1) atoms to form a mixture of distorted edge, corner, and face-sharing CoNp4Ge4 tetrahedra. All Co(1)-Ge(1) bond lengths are 2.32 Å. Ge(1) is bonded in a 9-coordinate geometry to four equivalent Np(1), four equivalent Co(1), and one Ge(1) atom. The Ge(1)-Ge(1) bond length is 2.61 Å.