Ca4PbN4 crystallizes in the orthorhombic Pnma space group. There are four inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a rectangular see-saw-like geometry to one N(1), one N(4), and two equivalent N(2) atoms. In the second Ca site, Ca(2) is bonded in a 6-coordinate geometry to one N(1), two equivalent N(2), and three equivalent N(3) atoms. In the third Ca site, Ca(3) is bonded in a 5-coordinate geometry to one Pb(1), two equivalent N(1), and two equivalent N(4) atoms. In the fourth Ca site, Ca(4) is bonded to one N(2), two equivalent N(1), and two equivalent N(4) atoms to form edge-sharing CaN5 square pyramids. Pb(1) is bonded in a 2-coordinate geometry to one Ca(3) and one N(4) atom. There are four inequivalent N sites. In the first N site, N(4) is bonded to one Ca(1), two equivalent Ca(3), two equivalent Ca(4), and one Pb(1) atom to form NCa5Pb octahedra that share corners with four equivalent N(1)Ca6 octahedra,  an edgeedge with one N(1)Ca6 octahedra, edges with two equivalent N(2)Ca5N octahedra, edges with two equivalent N(4)Ca5Pb octahedra, and  a faceface with one N(1)Ca6 octahedra. The corner-sharing octahedral tilt angles range from 0-40°. In the second N site, N(1) is bonded to one Ca(1), one Ca(2), two equivalent Ca(3), and two equivalent Ca(4) atoms to form NCa6 octahedra that share corners with two equivalent N(2)Ca5N octahedra, corners with four equivalent N(4)Ca5Pb octahedra,  an edgeedge with one N(4)Ca5Pb octahedra, edges with two equivalent N(2)Ca5N octahedra, edges with two equivalent N(1)Ca6 octahedra, and  a faceface with one N(4)Ca5Pb octahedra. The corner-sharing octahedral tilt angles range from 0-47°. In the third N site, N(2) is bonded to one Ca(4), two equivalent Ca(1), two equivalent Ca(2), and one N(3) atom to form NCa5N octahedra that share corners with two equivalent N(1)Ca6 octahedra, edges with two equivalent N(2)Ca5N octahedra, edges with two equivalent N(4)Ca5Pb octahedra, and edges with two equivalent N(1)Ca6 octahedra. The corner-sharing octahedral tilt angles are 47°. In the fourth N site, N(3) is bonded in a 4-coordinate geometry to three equivalent Ca(2) and one N(2) atom.
Ca4PbN4 crystallizes in the orthorhombic Pnma space group. There are four inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a rectangular see-saw-like geometry to one N(1), one N(4), and two equivalent N(2) atoms. The Ca(1)-N(1) bond length is 2.41 Å. The Ca(1)-N(4) bond length is 2.31 Å. Both Ca(1)-N(2) bond lengths are 2.49 Å. In the second Ca site, Ca(2) is bonded in a 6-coordinate geometry to one N(1), two equivalent N(2), and three equivalent N(3) atoms. The Ca(2)-N(1) bond length is 2.44 Å. Both Ca(2)-N(2) bond lengths are 2.52 Å. There is one shorter (2.24 Å) and two longer (2.55 Å) Ca(2)-N(3) bond lengths. In the third Ca site, Ca(3) is bonded in a 5-coordinate geometry to one Pb(1), two equivalent N(1), and two equivalent N(4) atoms. The Ca(3)-Pb(1) bond length is 3.26 Å. Both Ca(3)-N(1) bond lengths are 2.51 Å. Both Ca(3)-N(4) bond lengths are 2.55 Å. In the fourth Ca site, Ca(4) is bonded to one N(2), two equivalent N(1), and two equivalent N(4) atoms to form edge-sharing CaN5 square pyramids. The Ca(4)-N(2) bond length is 2.40 Å. Both Ca(4)-N(1) bond lengths are 2.53 Å. Both Ca(4)-N(4) bond lengths are 2.54 Å. Pb(1) is bonded in a 2-coordinate geometry to one Ca(3) and one N(4) atom. The Pb(1)-N(4) bond length is 2.23 Å. There are four inequivalent N sites. In the first N site, N(4) is bonded to one Ca(1), two equivalent Ca(3), two equivalent Ca(4), and one Pb(1) atom to form NCa5Pb octahedra that share corners with four equivalent N(1)Ca6 octahedra,  an edgeedge with one N(1)Ca6 octahedra, edges with two equivalent N(2)Ca5N octahedra, edges with two equivalent N(4)Ca5Pb octahedra, and  a faceface with one N(1)Ca6 octahedra. The corner-sharing octahedral tilt angles range from 0-40°. In the second N site, N(1) is bonded to one Ca(1), one Ca(2), two equivalent Ca(3), and two equivalent Ca(4) atoms to form NCa6 octahedra that share corners with two equivalent N(2)Ca5N octahedra, corners with four equivalent N(4)Ca5Pb octahedra,  an edgeedge with one N(4)Ca5Pb octahedra, edges with two equivalent N(2)Ca5N octahedra, edges with two equivalent N(1)Ca6 octahedra, and  a faceface with one N(4)Ca5Pb octahedra. The corner-sharing octahedral tilt angles range from 0-47°. In the third N site, N(2) is bonded to one Ca(4), two equivalent Ca(1), two equivalent Ca(2), and one N(3) atom to form NCa5N octahedra that share corners with two equivalent N(1)Ca6 octahedra, edges with two equivalent N(2)Ca5N octahedra, edges with two equivalent N(4)Ca5Pb octahedra, and edges with two equivalent N(1)Ca6 octahedra. The corner-sharing octahedral tilt angles are 47°. The N(2)-N(3) bond length is 1.28 Å. In the fourth N site, N(3) is bonded in a 4-coordinate geometry to three equivalent Ca(2) and one N(2) atom.