Na6Ge2S7 crystallizes in the monoclinic C2/c space group. There are four inequivalent Na sites. In the first Na site, Na(1) is bonded in a 6-coordinate geometry to one S(3), one S(4), two equivalent S(1), and two equivalent S(2) atoms. In the second Na site, Na(2) is bonded in a 4-coordinate geometry to one S(1), two equivalent S(2), and two equivalent S(3) atoms. In the third Na site, Na(3) is bonded in a 4-coordinate geometry to two equivalent S(1) and two equivalent S(3) atoms. In the fourth Na site, Na(4) is bonded to two equivalent S(1), two equivalent S(2), and two equivalent S(3) atoms to form NaS6 octahedra that share corners with two equivalent Ge(1)S4 tetrahedra and edges with two equivalent Ge(1)S4 tetrahedra. Ge(1) is bonded to one S(1), one S(2), one S(3), and one S(4) atom to form GeS4 tetrahedra that share  a cornercorner with one Na(4)S6 octahedra,  a cornercorner with one Ge(1)S4 tetrahedra, and  an edgeedge with one Na(4)S6 octahedra. The corner-sharing octahedral tilt angles are 20°. There are four inequivalent S sites. In the first S site, S(1) is bonded to one Na(2), one Na(3), one Na(4), two equivalent Na(1), and one Ge(1) atom to form a mixture of distorted edge and corner-sharing SNa5Ge octahedra. The corner-sharing octahedral tilt angles range from 0-78°. In the second S site, S(2) is bonded to one Na(4), two equivalent Na(1), two equivalent Na(2), and one Ge(1) atom to form a mixture of edge and corner-sharing SNa5Ge octahedra. The corner-sharing octahedral tilt angles range from 0-5°. In the third S site, S(3) is bonded in a 6-coordinate geometry to one Na(1), one Na(3), one Na(4), two equivalent Na(2), and one Ge(1) atom. In the fourth S site, S(4) is bonded in a 2-coordinate geometry to two equivalent Na(1) and two equivalent Ge(1) atoms.
Na6Ge2S7 crystallizes in the monoclinic C2/c space group. There are four inequivalent Na sites. In the first Na site, Na(1) is bonded in a 6-coordinate geometry to one S(3), one S(4), two equivalent S(1), and two equivalent S(2) atoms. The Na(1)-S(3) bond length is 2.85 Å. The Na(1)-S(4) bond length is 3.29 Å. There is one shorter (2.85 Å) and one longer (3.09 Å) Na(1)-S(1) bond length. There is one shorter (2.86 Å) and one longer (2.87 Å) Na(1)-S(2) bond length. In the second Na site, Na(2) is bonded in a 4-coordinate geometry to one S(1), two equivalent S(2), and two equivalent S(3) atoms. The Na(2)-S(1) bond length is 2.86 Å. There is one shorter (2.85 Å) and one longer (2.91 Å) Na(2)-S(2) bond length. There is one shorter (2.85 Å) and one longer (3.33 Å) Na(2)-S(3) bond length. In the third Na site, Na(3) is bonded in a 4-coordinate geometry to two equivalent S(1) and two equivalent S(3) atoms. Both Na(3)-S(1) bond lengths are 2.71 Å. Both Na(3)-S(3) bond lengths are 2.77 Å. In the fourth Na site, Na(4) is bonded to two equivalent S(1), two equivalent S(2), and two equivalent S(3) atoms to form NaS6 octahedra that share corners with two equivalent Ge(1)S4 tetrahedra and edges with two equivalent Ge(1)S4 tetrahedra. Both Na(4)-S(1) bond lengths are 3.08 Å. Both Na(4)-S(2) bond lengths are 2.75 Å. Both Na(4)-S(3) bond lengths are 2.95 Å. Ge(1) is bonded to one S(1), one S(2), one S(3), and one S(4) atom to form GeS4 tetrahedra that share  a cornercorner with one Na(4)S6 octahedra,  a cornercorner with one Ge(1)S4 tetrahedra, and  an edgeedge with one Na(4)S6 octahedra. The corner-sharing octahedral tilt angles are 20°. The Ge(1)-S(1) bond length is 2.19 Å. The Ge(1)-S(2) bond length is 2.22 Å. The Ge(1)-S(3) bond length is 2.20 Å. The Ge(1)-S(4) bond length is 2.27 Å. There are four inequivalent S sites. In the first S site, S(1) is bonded to one Na(2), one Na(3), one Na(4), two equivalent Na(1), and one Ge(1) atom to form a mixture of distorted edge and corner-sharing SNa5Ge octahedra. The corner-sharing octahedral tilt angles range from 0-78°. In the second S site, S(2) is bonded to one Na(4), two equivalent Na(1), two equivalent Na(2), and one Ge(1) atom to form a mixture of edge and corner-sharing SNa5Ge octahedra. The corner-sharing octahedral tilt angles range from 0-5°. In the third S site, S(3) is bonded in a 6-coordinate geometry to one Na(1), one Na(3), one Na(4), two equivalent Na(2), and one Ge(1) atom. In the fourth S site, S(4) is bonded in a 2-coordinate geometry to two equivalent Na(1) and two equivalent Ge(1) atoms.