MgNp3 is alpha La-derived structured and crystallizes in the tetragonal I4/mmm space group. Mg(1) is bonded to four equivalent Np(1) and eight equivalent Np(2) atoms to form MgNp12 cuboctahedra that share corners with four equivalent Mg(1)Np12 cuboctahedra, corners with eight equivalent Np(1)Mg4Np8 cuboctahedra, edges with eight equivalent Mg(1)Np12 cuboctahedra, edges with sixteen equivalent Np(2)Mg4Np8 cuboctahedra, faces with four equivalent Mg(1)Np12 cuboctahedra, faces with six equivalent Np(1)Mg4Np8 cuboctahedra, and faces with eight equivalent Np(2)Mg4Np8 cuboctahedra. There are two inequivalent Np sites. In the first Np site, Np(1) is bonded to four equivalent Mg(1) and eight equivalent Np(2) atoms to form NpMg4Np8 cuboctahedra that share corners with four equivalent Np(1)Mg4Np8 cuboctahedra, corners with eight equivalent Mg(1)Np12 cuboctahedra, edges with eight equivalent Np(1)Mg4Np8 cuboctahedra, edges with sixteen equivalent Np(2)Mg4Np8 cuboctahedra, faces with four equivalent Np(1)Mg4Np8 cuboctahedra, faces with six equivalent Mg(1)Np12 cuboctahedra, and faces with eight equivalent Np(2)Mg4Np8 cuboctahedra. In the second Np site, Np(2) is bonded to four equivalent Mg(1), four equivalent Np(1), and four equivalent Np(2) atoms to form NpMg4Np8 cuboctahedra that share corners with twelve equivalent Np(2)Mg4Np8 cuboctahedra, edges with eight equivalent Mg(1)Np12 cuboctahedra, edges with eight equivalent Np(1)Mg4Np8 cuboctahedra, edges with eight equivalent Np(2)Mg4Np8 cuboctahedra, faces with four equivalent Mg(1)Np12 cuboctahedra, faces with four equivalent Np(1)Mg4Np8 cuboctahedra, and faces with ten equivalent Np(2)Mg4Np8 cuboctahedra.
MgNp3 is alpha La-derived structured and crystallizes in the tetragonal I4/mmm space group. Mg(1) is bonded to four equivalent Np(1) and eight equivalent Np(2) atoms to form MgNp12 cuboctahedra that share corners with four equivalent Mg(1)Np12 cuboctahedra, corners with eight equivalent Np(1)Mg4Np8 cuboctahedra, edges with eight equivalent Mg(1)Np12 cuboctahedra, edges with sixteen equivalent Np(2)Mg4Np8 cuboctahedra, faces with four equivalent Mg(1)Np12 cuboctahedra, faces with six equivalent Np(1)Mg4Np8 cuboctahedra, and faces with eight equivalent Np(2)Mg4Np8 cuboctahedra. All Mg(1)-Np(1) bond lengths are 3.10 Å. All Mg(1)-Np(2) bond lengths are 3.06 Å. There are two inequivalent Np sites. In the first Np site, Np(1) is bonded to four equivalent Mg(1) and eight equivalent Np(2) atoms to form NpMg4Np8 cuboctahedra that share corners with four equivalent Np(1)Mg4Np8 cuboctahedra, corners with eight equivalent Mg(1)Np12 cuboctahedra, edges with eight equivalent Np(1)Mg4Np8 cuboctahedra, edges with sixteen equivalent Np(2)Mg4Np8 cuboctahedra, faces with four equivalent Np(1)Mg4Np8 cuboctahedra, faces with six equivalent Mg(1)Np12 cuboctahedra, and faces with eight equivalent Np(2)Mg4Np8 cuboctahedra. All Np(1)-Np(2) bond lengths are 3.06 Å. In the second Np site, Np(2) is bonded to four equivalent Mg(1), four equivalent Np(1), and four equivalent Np(2) atoms to form NpMg4Np8 cuboctahedra that share corners with twelve equivalent Np(2)Mg4Np8 cuboctahedra, edges with eight equivalent Mg(1)Np12 cuboctahedra, edges with eight equivalent Np(1)Mg4Np8 cuboctahedra, edges with eight equivalent Np(2)Mg4Np8 cuboctahedra, faces with four equivalent Mg(1)Np12 cuboctahedra, faces with four equivalent Np(1)Mg4Np8 cuboctahedra, and faces with ten equivalent Np(2)Mg4Np8 cuboctahedra. All Np(2)-Np(2) bond lengths are 3.10 Å.