Ca3Sc2N4 crystallizes in the monoclinic C2/c space group. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded to two equivalent N(2) and three equivalent N(1) atoms to form distorted CaN5 square pyramids that share corners with four equivalent Ca(2)N6 octahedra, corners with two equivalent Ca(1)N5 square pyramids, corners with six equivalent Sc(1)N4 tetrahedra, edges with three equivalent Ca(1)N5 square pyramids, edges with two equivalent Sc(1)N4 tetrahedra, and  a faceface with one Ca(2)N6 octahedra. The corner-sharing octahedral tilt angles range from 37-59°. In the second Ca site, Ca(2) is bonded to two equivalent N(1) and four equivalent N(2) atoms to form CaN6 octahedra that share corners with eight equivalent Ca(1)N5 square pyramids, corners with four equivalent Sc(1)N4 tetrahedra, edges with two equivalent Ca(2)N6 octahedra, edges with four equivalent Sc(1)N4 tetrahedra, and faces with two equivalent Ca(1)N5 square pyramids. Sc(1) is bonded to two equivalent N(1) and two equivalent N(2) atoms to form ScN4 tetrahedra that share corners with two equivalent Ca(2)N6 octahedra, corners with six equivalent Ca(1)N5 square pyramids, corners with two equivalent Sc(1)N4 tetrahedra, edges with two equivalent Ca(2)N6 octahedra, edges with two equivalent Ca(1)N5 square pyramids, and  an edgeedge with one Sc(1)N4 tetrahedra. The corner-sharing octahedral tilt angles range from 30-55°. There are two inequivalent N sites. In the first N site, N(1) is bonded to one Ca(2), three equivalent Ca(1), and two equivalent Sc(1) atoms to form a mixture of distorted edge, face, and corner-sharing NCa4Sc2 pentagonal pyramids. In the second N site, N(2) is bonded in a 6-coordinate geometry to two equivalent Ca(1), two equivalent Ca(2), and two equivalent Sc(1) atoms.
Ca3Sc2N4 crystallizes in the monoclinic C2/c space group. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded to two equivalent N(2) and three equivalent N(1) atoms to form distorted CaN5 square pyramids that share corners with four equivalent Ca(2)N6 octahedra, corners with two equivalent Ca(1)N5 square pyramids, corners with six equivalent Sc(1)N4 tetrahedra, edges with three equivalent Ca(1)N5 square pyramids, edges with two equivalent Sc(1)N4 tetrahedra, and  a faceface with one Ca(2)N6 octahedra. The corner-sharing octahedral tilt angles range from 37-59°. There is one shorter (2.51 Å) and one longer (2.67 Å) Ca(1)-N(2) bond length. There are a spread of Ca(1)-N(1) bond distances ranging from 2.57-2.59 Å. In the second Ca site, Ca(2) is bonded to two equivalent N(1) and four equivalent N(2) atoms to form CaN6 octahedra that share corners with eight equivalent Ca(1)N5 square pyramids, corners with four equivalent Sc(1)N4 tetrahedra, edges with two equivalent Ca(2)N6 octahedra, edges with four equivalent Sc(1)N4 tetrahedra, and faces with two equivalent Ca(1)N5 square pyramids. Both Ca(2)-N(1) bond lengths are 2.60 Å. There are two shorter (2.51 Å) and two longer (2.54 Å) Ca(2)-N(2) bond lengths. Sc(1) is bonded to two equivalent N(1) and two equivalent N(2) atoms to form ScN4 tetrahedra that share corners with two equivalent Ca(2)N6 octahedra, corners with six equivalent Ca(1)N5 square pyramids, corners with two equivalent Sc(1)N4 tetrahedra, edges with two equivalent Ca(2)N6 octahedra, edges with two equivalent Ca(1)N5 square pyramids, and  an edgeedge with one Sc(1)N4 tetrahedra. The corner-sharing octahedral tilt angles range from 30-55°. There is one shorter (2.11 Å) and one longer (2.21 Å) Sc(1)-N(1) bond length. Both Sc(1)-N(2) bond lengths are 2.11 Å. There are two inequivalent N sites. In the first N site, N(1) is bonded to one Ca(2), three equivalent Ca(1), and two equivalent Sc(1) atoms to form a mixture of distorted edge, face, and corner-sharing NCa4Sc2 pentagonal pyramids. In the second N site, N(2) is bonded in a 6-coordinate geometry to two equivalent Ca(1), two equivalent Ca(2), and two equivalent Sc(1) atoms.