NaHfCuSe3 crystallizes in the orthorhombic Pnma space group. Na(1) is bonded in a 7-coordinate geometry to two equivalent Se(1), two equivalent Se(2), and three equivalent Se(3) atoms. Hf(1) is bonded to one Se(2), two equivalent Se(3), and three equivalent Se(1) atoms to form distorted HfSe6 octahedra that share  a cornercorner with one Cu(1)Se4 tetrahedra, edges with four equivalent Hf(1)Se6 octahedra, and edges with two equivalent Cu(1)Se4 tetrahedra. Cu(1) is bonded to one Se(3) and three equivalent Se(2) atoms to form distorted CuSe4 tetrahedra that share  a cornercorner with one Hf(1)Se6 octahedra, corners with two equivalent Cu(1)Se4 tetrahedra, edges with two equivalent Hf(1)Se6 octahedra, and edges with two equivalent Cu(1)Se4 tetrahedra. The corner-sharing octahedral tilt angles are 69°. There are three inequivalent Se sites. In the first Se site, Se(1) is bonded to two equivalent Na(1) and three equivalent Hf(1) atoms to form edge-sharing SeNa2Hf3 trigonal bipyramids. In the second Se site, Se(2) is bonded in a 6-coordinate geometry to two equivalent Na(1), one Hf(1), and three equivalent Cu(1) atoms. In the third Se site, Se(3) is bonded in a 6-coordinate geometry to three equivalent Na(1), two equivalent Hf(1), and one Cu(1) atom.
NaHfCuSe3 crystallizes in the orthorhombic Pnma space group. Na(1) is bonded in a 7-coordinate geometry to two equivalent Se(1), two equivalent Se(2), and three equivalent Se(3) atoms. Both Na(1)-Se(1) bond lengths are 3.00 Å. Both Na(1)-Se(2) bond lengths are 3.04 Å. There are two shorter (3.14 Å) and one longer (3.48 Å) Na(1)-Se(3) bond length. Hf(1) is bonded to one Se(2), two equivalent Se(3), and three equivalent Se(1) atoms to form distorted HfSe6 octahedra that share  a cornercorner with one Cu(1)Se4 tetrahedra, edges with four equivalent Hf(1)Se6 octahedra, and edges with two equivalent Cu(1)Se4 tetrahedra. The Hf(1)-Se(2) bond length is 2.59 Å. Both Hf(1)-Se(3) bond lengths are 2.66 Å. There are two shorter (2.71 Å) and one longer (2.77 Å) Hf(1)-Se(1) bond length. Cu(1) is bonded to one Se(3) and three equivalent Se(2) atoms to form distorted CuSe4 tetrahedra that share  a cornercorner with one Hf(1)Se6 octahedra, corners with two equivalent Cu(1)Se4 tetrahedra, edges with two equivalent Hf(1)Se6 octahedra, and edges with two equivalent Cu(1)Se4 tetrahedra. The corner-sharing octahedral tilt angles are 69°. The Cu(1)-Se(3) bond length is 2.42 Å. There are two shorter (2.47 Å) and one longer (2.52 Å) Cu(1)-Se(2) bond length. There are three inequivalent Se sites. In the first Se site, Se(1) is bonded to two equivalent Na(1) and three equivalent Hf(1) atoms to form edge-sharing SeNa2Hf3 trigonal bipyramids. In the second Se site, Se(2) is bonded in a 6-coordinate geometry to two equivalent Na(1), one Hf(1), and three equivalent Cu(1) atoms. In the third Se site, Se(3) is bonded in a 6-coordinate geometry to three equivalent Na(1), two equivalent Hf(1), and one Cu(1) atom.