PbGe4O9 crystallizes in the trigonal P321 space group. Pb(1) is bonded in a distorted rectangular see-saw-like geometry to two equivalent O(1) and two equivalent O(4) atoms. There are four inequivalent Ge sites. In the first Ge site, Ge(1) is bonded to one O(2), one O(3), one O(4), and one O(5) atom to form GeO4 tetrahedra that share corners with two equivalent Ge(3)O6 octahedra,  a cornercorner with one Ge(1)O4 tetrahedra, and  a cornercorner with one Ge(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 57-61°. In the second Ge site, Ge(2) is bonded to two equivalent O(1) and two equivalent O(2) atoms to form GeO4 tetrahedra that share corners with two equivalent Ge(4)O6 octahedra and corners with two equivalent Ge(1)O4 tetrahedra. The corner-sharing octahedral tilt angles are 62°. In the third Ge site, Ge(3) is bonded to three equivalent O(3) and three equivalent O(4) atoms to form corner-sharing GeO6 octahedra. In the fourth Ge site, Ge(4) is bonded to six equivalent O(1) atoms to form corner-sharing GeO6 octahedra. There are five inequivalent O sites. In the first O site, O(4) is bonded in a distorted bent 120 degrees geometry to one Pb(1), one Ge(1), and one Ge(3) atom. In the second O site, O(5) is bonded in a bent 120 degrees geometry to two equivalent Ge(1) atoms. In the third O site, O(1) is bonded in a distorted bent 120 degrees geometry to one Pb(1), one Ge(2), and one Ge(4) atom. In the fourth O site, O(2) is bonded in a bent 120 degrees geometry to one Ge(1) and one Ge(2) atom. In the fifth O site, O(3) is bonded in a bent 120 degrees geometry to one Ge(1) and one Ge(3) atom.
PbGe4O9 crystallizes in the trigonal P321 space group. Pb(1) is bonded in a distorted rectangular see-saw-like geometry to two equivalent O(1) and two equivalent O(4) atoms. Both Pb(1)-O(1) bond lengths are 2.67 Å. Both Pb(1)-O(4) bond lengths are 2.67 Å. There are four inequivalent Ge sites. In the first Ge site, Ge(1) is bonded to one O(2), one O(3), one O(4), and one O(5) atom to form GeO4 tetrahedra that share corners with two equivalent Ge(3)O6 octahedra,  a cornercorner with one Ge(1)O4 tetrahedra, and  a cornercorner with one Ge(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 57-61°. The Ge(1)-O(2) bond length is 1.80 Å. The Ge(1)-O(3) bond length is 1.77 Å. The Ge(1)-O(4) bond length is 1.77 Å. The Ge(1)-O(5) bond length is 1.78 Å. In the second Ge site, Ge(2) is bonded to two equivalent O(1) and two equivalent O(2) atoms to form GeO4 tetrahedra that share corners with two equivalent Ge(4)O6 octahedra and corners with two equivalent Ge(1)O4 tetrahedra. The corner-sharing octahedral tilt angles are 62°. Both Ge(2)-O(1) bond lengths are 1.79 Å. Both Ge(2)-O(2) bond lengths are 1.81 Å. In the third Ge site, Ge(3) is bonded to three equivalent O(3) and three equivalent O(4) atoms to form corner-sharing GeO6 octahedra. All Ge(3)-O(3) bond lengths are 1.89 Å. All Ge(3)-O(4) bond lengths are 1.90 Å. In the fourth Ge site, Ge(4) is bonded to six equivalent O(1) atoms to form corner-sharing GeO6 octahedra. All Ge(4)-O(1) bond lengths are 1.93 Å. There are five inequivalent O sites. In the first O site, O(4) is bonded in a distorted bent 120 degrees geometry to one Pb(1), one Ge(1), and one Ge(3) atom. In the second O site, O(5) is bonded in a bent 120 degrees geometry to two equivalent Ge(1) atoms. In the third O site, O(1) is bonded in a distorted bent 120 degrees geometry to one Pb(1), one Ge(2), and one Ge(4) atom. In the fourth O site, O(2) is bonded in a bent 120 degrees geometry to one Ge(1) and one Ge(2) atom. In the fifth O site, O(3) is bonded in a bent 120 degrees geometry to one Ge(1) and one Ge(3) atom.