Ca4TiN4 crystallizes in the triclinic P-1 space group. There are four inequivalent Ca sites. In the first Ca site, Ca(1) is bonded to one N(3), two equivalent N(1), and two equivalent N(2) atoms to form CaN5 square pyramids that share corners with three equivalent Ca(4)N5 square pyramids,  a cornercorner with one Ti(1)N4 tetrahedra, corners with two equivalent Ca(3)N4 trigonal pyramids, edges with two equivalent Ca(1)N5 square pyramids, edges with three equivalent Ca(4)N5 square pyramids, and edges with two equivalent Ti(1)N4 tetrahedra. In the second Ca site, Ca(2) is bonded in a 5-coordinate geometry to one N(1), one N(2), one N(3), and two equivalent N(4) atoms. In the third Ca site, Ca(3) is bonded to two equivalent N(3) and two equivalent N(4) atoms to form distorted CaN4 trigonal pyramids that share corners with two equivalent Ca(1)N5 square pyramids, corners with two equivalent Ca(4)N5 square pyramids, corners with four equivalent Ti(1)N4 tetrahedra, and edges with two equivalent Ca(3)N4 trigonal pyramids. In the fourth Ca site, Ca(4) is bonded to one N(3), two equivalent N(1), and two equivalent N(2) atoms to form CaN5 square pyramids that share corners with three equivalent Ca(1)N5 square pyramids, corners with three equivalent Ti(1)N4 tetrahedra, corners with two equivalent Ca(3)N4 trigonal pyramids, edges with two equivalent Ca(4)N5 square pyramids, edges with three equivalent Ca(1)N5 square pyramids, and  an edgeedge with one Ti(1)N4 tetrahedra. Ti(1) is bonded to one N(1), one N(2), one N(3), and one N(4) atom to form TiN4 tetrahedra that share  a cornercorner with one Ca(1)N5 square pyramid, corners with three equivalent Ca(4)N5 square pyramids, corners with four equivalent Ca(3)N4 trigonal pyramids,  an edgeedge with one Ca(4)N5 square pyramid, and edges with two equivalent Ca(1)N5 square pyramids. There are four inequivalent N sites. In the first N site, N(1) is bonded to one Ca(2), two equivalent Ca(1), two equivalent Ca(4), and one Ti(1) atom to form a mixture of corner and edge-sharing NCa5Ti octahedra. The corner-sharing octahedral tilt angles range from 6-21°. In the second N site, N(2) is bonded to one Ca(2), two equivalent Ca(1), two equivalent Ca(4), and one Ti(1) atom to form a mixture of distorted corner and edge-sharing NCa5Ti octahedra. The corner-sharing octahedral tilt angles range from 6-21°. In the third N site, N(3) is bonded to one Ca(1), one Ca(2), one Ca(4), two equivalent Ca(3), and one Ti(1) atom to form a mixture of corner and edge-sharing NCa5Ti octahedra. The corner-sharing octahedral tilt angles range from 12-16°. In the fourth N site, N(4) is bonded in a 5-coordinate geometry to two equivalent Ca(2), two equivalent Ca(3), and one Ti(1) atom.
Ca4TiN4 crystallizes in the triclinic P-1 space group. There are four inequivalent Ca sites. In the first Ca site, Ca(1) is bonded to one N(3), two equivalent N(1), and two equivalent N(2) atoms to form CaN5 square pyramids that share corners with three equivalent Ca(4)N5 square pyramids,  a cornercorner with one Ti(1)N4 tetrahedra, corners with two equivalent Ca(3)N4 trigonal pyramids, edges with two equivalent Ca(1)N5 square pyramids, edges with three equivalent Ca(4)N5 square pyramids, and edges with two equivalent Ti(1)N4 tetrahedra. The Ca(1)-N(3) bond length is 2.49 Å. There is one shorter (2.44 Å) and one longer (2.54 Å) Ca(1)-N(1) bond length. There is one shorter (2.58 Å) and one longer (2.59 Å) Ca(1)-N(2) bond length. In the second Ca site, Ca(2) is bonded in a 5-coordinate geometry to one N(1), one N(2), one N(3), and two equivalent N(4) atoms. The Ca(2)-N(1) bond length is 2.46 Å. The Ca(2)-N(2) bond length is 2.56 Å. The Ca(2)-N(3) bond length is 2.48 Å. There is one shorter (2.42 Å) and one longer (2.84 Å) Ca(2)-N(4) bond length. In the third Ca site, Ca(3) is bonded to two equivalent N(3) and two equivalent N(4) atoms to form distorted CaN4 trigonal pyramids that share corners with two equivalent Ca(1)N5 square pyramids, corners with two equivalent Ca(4)N5 square pyramids, corners with four equivalent Ti(1)N4 tetrahedra, and edges with two equivalent Ca(3)N4 trigonal pyramids. There is one shorter (2.39 Å) and one longer (2.48 Å) Ca(3)-N(3) bond length. There is one shorter (2.39 Å) and one longer (2.42 Å) Ca(3)-N(4) bond length. In the fourth Ca site, Ca(4) is bonded to one N(3), two equivalent N(1), and two equivalent N(2) atoms to form CaN5 square pyramids that share corners with three equivalent Ca(1)N5 square pyramids, corners with three equivalent Ti(1)N4 tetrahedra, corners with two equivalent Ca(3)N4 trigonal pyramids, edges with two equivalent Ca(4)N5 square pyramids, edges with three equivalent Ca(1)N5 square pyramids, and  an edgeedge with one Ti(1)N4 tetrahedra. The Ca(4)-N(3) bond length is 2.48 Å. There is one shorter (2.40 Å) and one longer (2.46 Å) Ca(4)-N(1) bond length. There is one shorter (2.49 Å) and one longer (2.50 Å) Ca(4)-N(2) bond length. Ti(1) is bonded to one N(1), one N(2), one N(3), and one N(4) atom to form TiN4 tetrahedra that share  a cornercorner with one Ca(1)N5 square pyramid, corners with three equivalent Ca(4)N5 square pyramids, corners with four equivalent Ca(3)N4 trigonal pyramids,  an edgeedge with one Ca(4)N5 square pyramid, and edges with two equivalent Ca(1)N5 square pyramids. The Ti(1)-N(1) bond length is 1.94 Å. The Ti(1)-N(2) bond length is 1.97 Å. The Ti(1)-N(3) bond length is 1.96 Å. The Ti(1)-N(4) bond length is 1.94 Å. There are four inequivalent N sites. In the first N site, N(1) is bonded to one Ca(2), two equivalent Ca(1), two equivalent Ca(4), and one Ti(1) atom to form a mixture of corner and edge-sharing NCa5Ti octahedra. The corner-sharing octahedral tilt angles range from 6-21°. In the second N site, N(2) is bonded to one Ca(2), two equivalent Ca(1), two equivalent Ca(4), and one Ti(1) atom to form a mixture of distorted corner and edge-sharing NCa5Ti octahedra. The corner-sharing octahedral tilt angles range from 6-21°. In the third N site, N(3) is bonded to one Ca(1), one Ca(2), one Ca(4), two equivalent Ca(3), and one Ti(1) atom to form a mixture of corner and edge-sharing NCa5Ti octahedra. The corner-sharing octahedral tilt angles range from 12-16°. In the fourth N site, N(4) is bonded in a 5-coordinate geometry to two equivalent Ca(2), two equivalent Ca(3), and one Ti(1) atom.