NaNp3 is alpha bismuth trifluoride structured and crystallizes in the tetragonal I4/mmm space group. Na(1) is bonded to four equivalent Np(2) and eight equivalent Np(1) atoms to form NaNp12 cuboctahedra that share corners with four equivalent Na(1)Np12 cuboctahedra, corners with eight equivalent Np(2)Na4Np8 cuboctahedra, edges with eight equivalent Na(1)Np12 cuboctahedra, edges with sixteen equivalent Np(1)Na4Np8 cuboctahedra, faces with four equivalent Na(1)Np12 cuboctahedra, faces with six equivalent Np(2)Na4Np8 cuboctahedra, and faces with eight equivalent Np(1)Na4Np8 cuboctahedra. There are two inequivalent Np sites. In the first Np site, Np(1) is bonded to four equivalent Na(1), four equivalent Np(1), and four equivalent Np(2) atoms to form distorted NpNa4Np8 cuboctahedra that share corners with twelve equivalent Np(1)Na4Np8 cuboctahedra, edges with eight equivalent Na(1)Np12 cuboctahedra, edges with eight equivalent Np(1)Na4Np8 cuboctahedra, edges with eight equivalent Np(2)Na4Np8 cuboctahedra, faces with four equivalent Na(1)Np12 cuboctahedra, faces with four equivalent Np(2)Na4Np8 cuboctahedra, and faces with ten equivalent Np(1)Na4Np8 cuboctahedra. In the second Np site, Np(2) is bonded to four equivalent Na(1) and eight equivalent Np(1) atoms to form NpNa4Np8 cuboctahedra that share corners with four equivalent Np(2)Na4Np8 cuboctahedra, corners with eight equivalent Na(1)Np12 cuboctahedra, edges with eight equivalent Np(2)Na4Np8 cuboctahedra, edges with sixteen equivalent Np(1)Na4Np8 cuboctahedra, faces with four equivalent Np(2)Na4Np8 cuboctahedra, faces with six equivalent Na(1)Np12 cuboctahedra, and faces with eight equivalent Np(1)Na4Np8 cuboctahedra.
NaNp3 is alpha bismuth trifluoride structured and crystallizes in the tetragonal I4/mmm space group. Na(1) is bonded to four equivalent Np(2) and eight equivalent Np(1) atoms to form NaNp12 cuboctahedra that share corners with four equivalent Na(1)Np12 cuboctahedra, corners with eight equivalent Np(2)Na4Np8 cuboctahedra, edges with eight equivalent Na(1)Np12 cuboctahedra, edges with sixteen equivalent Np(1)Na4Np8 cuboctahedra, faces with four equivalent Na(1)Np12 cuboctahedra, faces with six equivalent Np(2)Na4Np8 cuboctahedra, and faces with eight equivalent Np(1)Na4Np8 cuboctahedra. All Na(1)-Np(2) bond lengths are 3.30 Å. All Na(1)-Np(1) bond lengths are 3.18 Å. There are two inequivalent Np sites. In the first Np site, Np(1) is bonded to four equivalent Na(1), four equivalent Np(1), and four equivalent Np(2) atoms to form distorted NpNa4Np8 cuboctahedra that share corners with twelve equivalent Np(1)Na4Np8 cuboctahedra, edges with eight equivalent Na(1)Np12 cuboctahedra, edges with eight equivalent Np(1)Na4Np8 cuboctahedra, edges with eight equivalent Np(2)Na4Np8 cuboctahedra, faces with four equivalent Na(1)Np12 cuboctahedra, faces with four equivalent Np(2)Na4Np8 cuboctahedra, and faces with ten equivalent Np(1)Na4Np8 cuboctahedra. All Np(1)-Np(1) bond lengths are 3.30 Å. All Np(1)-Np(2) bond lengths are 3.18 Å. In the second Np site, Np(2) is bonded to four equivalent Na(1) and eight equivalent Np(1) atoms to form NpNa4Np8 cuboctahedra that share corners with four equivalent Np(2)Na4Np8 cuboctahedra, corners with eight equivalent Na(1)Np12 cuboctahedra, edges with eight equivalent Np(2)Na4Np8 cuboctahedra, edges with sixteen equivalent Np(1)Na4Np8 cuboctahedra, faces with four equivalent Np(2)Na4Np8 cuboctahedra, faces with six equivalent Na(1)Np12 cuboctahedra, and faces with eight equivalent Np(1)Na4Np8 cuboctahedra.