HoFeGe2O7 crystallizes in the monoclinic C2/m space group. Ho(1) is bonded in a 6-coordinate geometry to two equivalent O(3), two equivalent O(4), and two equivalent O(5) atoms. Fe(1) is bonded to two equivalent O(2), two equivalent O(4), and two equivalent O(5) atoms to form distorted FeO6 octahedra that share corners with four equivalent Ge(1)O4 tetrahedra and  an edgeedge with one Fe(1)O6 octahedra. There are two inequivalent Ge sites. In the first Ge site, Ge(1) is bonded to one O(1), one O(2), and two equivalent O(4) atoms to form GeO4 tetrahedra that share corners with four equivalent Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 45-54°. In the second Ge site, Ge(2) is bonded in a 5-coordinate geometry to one O(1), one O(2), one O(3), and two equivalent O(5) atoms. There are five inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one Ge(1) and one Ge(2) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to two equivalent Fe(1), one Ge(1), and one Ge(2) atom. In the third O site, O(3) is bonded in a trigonal planar geometry to two equivalent Ho(1) and one Ge(2) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Ho(1), one Fe(1), and one Ge(1) atom. In the fifth O site, O(5) is bonded in a trigonal non-coplanar geometry to one Ho(1), one Fe(1), and one Ge(2) atom.
HoFeGe2O7 crystallizes in the monoclinic C2/m space group. Ho(1) is bonded in a 6-coordinate geometry to two equivalent O(3), two equivalent O(4), and two equivalent O(5) atoms. Both Ho(1)-O(3) bond lengths are 2.23 Å. Both Ho(1)-O(4) bond lengths are 2.42 Å. Both Ho(1)-O(5) bond lengths are 2.22 Å. Fe(1) is bonded to two equivalent O(2), two equivalent O(4), and two equivalent O(5) atoms to form distorted FeO6 octahedra that share corners with four equivalent Ge(1)O4 tetrahedra and  an edgeedge with one Fe(1)O6 octahedra. Both Fe(1)-O(2) bond lengths are 2.15 Å. Both Fe(1)-O(4) bond lengths are 2.02 Å. Both Fe(1)-O(5) bond lengths are 1.99 Å. There are two inequivalent Ge sites. In the first Ge site, Ge(1) is bonded to one O(1), one O(2), and two equivalent O(4) atoms to form GeO4 tetrahedra that share corners with four equivalent Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 45-54°. The Ge(1)-O(1) bond length is 1.79 Å. The Ge(1)-O(2) bond length is 1.80 Å. Both Ge(1)-O(4) bond lengths are 1.78 Å. In the second Ge site, Ge(2) is bonded in a 5-coordinate geometry to one O(1), one O(2), one O(3), and two equivalent O(5) atoms. The Ge(2)-O(1) bond length is 1.82 Å. The Ge(2)-O(2) bond length is 2.38 Å. The Ge(2)-O(3) bond length is 1.75 Å. Both Ge(2)-O(5) bond lengths are 1.77 Å. There are five inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one Ge(1) and one Ge(2) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to two equivalent Fe(1), one Ge(1), and one Ge(2) atom. In the third O site, O(3) is bonded in a trigonal planar geometry to two equivalent Ho(1) and one Ge(2) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Ho(1), one Fe(1), and one Ge(1) atom. In the fifth O site, O(5) is bonded in a trigonal non-coplanar geometry to one Ho(1), one Fe(1), and one Ge(2) atom.