Np3Si2 crystallizes in the tetragonal P4/mbm space group. There are two inequivalent Np sites. In the first Np site, Np(1) is bonded in a square co-planar geometry to four equivalent Si(1) atoms. In the second Np site, Np(2) is bonded in a 6-coordinate geometry to six equivalent Si(1) atoms. Si(1) is bonded in a 9-coordinate geometry to two equivalent Np(1), six equivalent Np(2), and one Si(1) atom.
Np3Si2 crystallizes in the tetragonal P4/mbm space group. There are two inequivalent Np sites. In the first Np site, Np(1) is bonded in a square co-planar geometry to four equivalent Si(1) atoms. All Np(1)-Si(1) bond lengths are 2.82 Å. In the second Np site, Np(2) is bonded in a 6-coordinate geometry to six equivalent Si(1) atoms. There are two shorter (2.76 Å) and four longer (2.90 Å) Np(2)-Si(1) bond lengths. Si(1) is bonded in a 9-coordinate geometry to two equivalent Np(1), six equivalent Np(2), and one Si(1) atom. The Si(1)-Si(1) bond length is 2.32 Å.