Ca4RuN4 crystallizes in the triclinic P-1 space group. There are four inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 5-coordinate geometry to one N(1), one N(3), one N(4), and two equivalent N(2) atoms. In the second Ca site, Ca(2) is bonded in a distorted see-saw-like geometry to two equivalent N(2) and two equivalent N(3) atoms. In the third Ca site, Ca(3) is bonded to one N(3), two equivalent N(1), and two equivalent N(4) atoms to form distorted CaN5 trigonal bipyramids that share corners with three equivalent Ru(1)N4 tetrahedra,  an edgeedge with one Ru(1)N4 tetrahedra, and edges with two equivalent Ca(3)N5 trigonal bipyramids. In the fourth Ca site, Ca(4) is bonded in a 6-coordinate geometry to one N(2), one N(3), two equivalent N(1), and two equivalent N(4) atoms. Ru(1) is bonded to one N(1), one N(2), one N(3), and one N(4) atom to form distorted RuN4 tetrahedra that share corners with three equivalent Ca(3)N5 trigonal bipyramids and  an edgeedge with one Ca(3)N5 trigonal bipyramid. There are four inequivalent N sites. In the first N site, N(1) is bonded to one Ca(1), two equivalent Ca(3), two equivalent Ca(4), and one Ru(1) atom to form a mixture of corner, edge, and face-sharing NCa5Ru octahedra. The corner-sharing octahedral tilt angles range from 14-63°. In the second N site, N(2) is bonded to one Ca(4), two equivalent Ca(1), two equivalent Ca(2), and one Ru(1) atom to form a mixture of corner, edge, and face-sharing NCa5Ru octahedra. The corner-sharing octahedral tilt angles range from 32-63°. In the third N site, N(3) is bonded to one Ca(1), one Ca(3), one Ca(4), two equivalent Ca(2), and one Ru(1) atom to form a mixture of corner, edge, and face-sharing NCa5Ru octahedra. The corner-sharing octahedral tilt angles range from 14-60°. In the fourth N site, N(4) is bonded in a 6-coordinate geometry to one Ca(1), two equivalent Ca(3), two equivalent Ca(4), and one Ru(1) atom.
Ca4RuN4 crystallizes in the triclinic P-1 space group. There are four inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 5-coordinate geometry to one N(1), one N(3), one N(4), and two equivalent N(2) atoms. The Ca(1)-N(1) bond length is 2.41 Å. The Ca(1)-N(3) bond length is 2.45 Å. The Ca(1)-N(4) bond length is 2.57 Å. There is one shorter (2.51 Å) and one longer (2.62 Å) Ca(1)-N(2) bond length. In the second Ca site, Ca(2) is bonded in a distorted see-saw-like geometry to two equivalent N(2) and two equivalent N(3) atoms. There is one shorter (2.35 Å) and one longer (2.48 Å) Ca(2)-N(2) bond length. There is one shorter (2.47 Å) and one longer (2.48 Å) Ca(2)-N(3) bond length. In the third Ca site, Ca(3) is bonded to one N(3), two equivalent N(1), and two equivalent N(4) atoms to form distorted CaN5 trigonal bipyramids that share corners with three equivalent Ru(1)N4 tetrahedra,  an edgeedge with one Ru(1)N4 tetrahedra, and edges with two equivalent Ca(3)N5 trigonal bipyramids. The Ca(3)-N(3) bond length is 2.37 Å. There is one shorter (2.35 Å) and one longer (2.38 Å) Ca(3)-N(1) bond length. There is one shorter (2.53 Å) and one longer (2.64 Å) Ca(3)-N(4) bond length. In the fourth Ca site, Ca(4) is bonded in a 6-coordinate geometry to one N(2), one N(3), two equivalent N(1), and two equivalent N(4) atoms. The Ca(4)-N(2) bond length is 2.57 Å. The Ca(4)-N(3) bond length is 2.50 Å. There is one shorter (2.48 Å) and one longer (2.53 Å) Ca(4)-N(1) bond length. There is one shorter (2.66 Å) and one longer (2.89 Å) Ca(4)-N(4) bond length. Ru(1) is bonded to one N(1), one N(2), one N(3), and one N(4) atom to form distorted RuN4 tetrahedra that share corners with three equivalent Ca(3)N5 trigonal bipyramids and  an edgeedge with one Ca(3)N5 trigonal bipyramid. The Ru(1)-N(1) bond length is 2.08 Å. The Ru(1)-N(2) bond length is 2.02 Å. The Ru(1)-N(3) bond length is 1.99 Å. The Ru(1)-N(4) bond length is 1.84 Å. There are four inequivalent N sites. In the first N site, N(1) is bonded to one Ca(1), two equivalent Ca(3), two equivalent Ca(4), and one Ru(1) atom to form a mixture of corner, edge, and face-sharing NCa5Ru octahedra. The corner-sharing octahedral tilt angles range from 14-63°. In the second N site, N(2) is bonded to one Ca(4), two equivalent Ca(1), two equivalent Ca(2), and one Ru(1) atom to form a mixture of corner, edge, and face-sharing NCa5Ru octahedra. The corner-sharing octahedral tilt angles range from 32-63°. In the third N site, N(3) is bonded to one Ca(1), one Ca(3), one Ca(4), two equivalent Ca(2), and one Ru(1) atom to form a mixture of corner, edge, and face-sharing NCa5Ru octahedra. The corner-sharing octahedral tilt angles range from 14-60°. In the fourth N site, N(4) is bonded in a 6-coordinate geometry to one Ca(1), two equivalent Ca(3), two equivalent Ca(4), and one Ru(1) atom.