Ho2MoFeO7 crystallizes in the triclinic P-1 space group. There are four inequivalent Ho sites. In the first Ho site, Ho(1) is bonded in a body-centered cubic geometry to two equivalent O(1), two equivalent O(2), two equivalent O(4), and two equivalent O(6) atoms. In the second Ho site, Ho(2) is bonded in a body-centered cubic geometry to two equivalent O(1), two equivalent O(2), two equivalent O(3), and two equivalent O(7) atoms. In the third Ho site, Ho(3) is bonded in a body-centered cubic geometry to two equivalent O(1), two equivalent O(3), two equivalent O(4), and two equivalent O(5) atoms. In the fourth Ho site, Ho(4) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms to form distorted HoO6 octahedra that share corners with two equivalent Mo(1)O6 octahedra, corners with two equivalent Fe(1)O6 octahedra, and corners with two equivalent Fe(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 61-63°. There are two inequivalent Mo sites. In the first Mo site, Mo(1) is bonded to two equivalent O(4), two equivalent O(5), and two equivalent O(6) atoms to form MoO6 octahedra that share corners with two equivalent Ho(4)O6 octahedra, corners with two equivalent Fe(1)O6 octahedra, corners with two equivalent Fe(2)O6 octahedra, and edges with two equivalent Mo(2)O8 hexagonal bipyramids. The corner-sharing octahedral tilt angles range from 49-61°. In the second Mo site, Mo(2) is bonded to two equivalent O(1), two equivalent O(5), two equivalent O(6), and two equivalent O(7) atoms to form distorted MoO8 hexagonal bipyramids that share edges with two equivalent Mo(1)O6 octahedra, edges with two equivalent Fe(1)O6 octahedra, and edges with two equivalent Fe(2)O6 octahedra. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to two equivalent O(2), two equivalent O(6), and two equivalent O(7) atoms to form distorted FeO6 octahedra that share corners with two equivalent Ho(4)O6 octahedra, corners with two equivalent Mo(1)O6 octahedra, corners with two equivalent Fe(2)O6 octahedra, and edges with two equivalent Mo(2)O8 hexagonal bipyramids. The corner-sharing octahedral tilt angles range from 49-63°. In the second Fe site, Fe(2) is bonded to two equivalent O(3), two equivalent O(5), and two equivalent O(7) atoms to form distorted FeO6 octahedra that share corners with two equivalent Ho(4)O6 octahedra, corners with two equivalent Mo(1)O6 octahedra, corners with two equivalent Fe(1)O6 octahedra, and edges with two equivalent Mo(2)O8 hexagonal bipyramids. The corner-sharing octahedral tilt angles range from 56-63°. There are seven inequivalent O sites. In the first O site, O(1) is bonded to one Ho(1), one Ho(2), one Ho(3), and one Mo(2) atom to form OHo3Mo tetrahedra that share corners with two equivalent O(2)Ho3Fe tetrahedra, corners with two equivalent O(3)Ho3Fe tetrahedra, corners with two equivalent O(4)Ho3Mo tetrahedra, corners with four equivalent O(1)Ho3Mo tetrahedra, corners with two equivalent O(7)HoFe2Mo trigonal pyramids, corners with two equivalent O(5)HoFeMo2 trigonal pyramids, corners with two equivalent O(6)HoFeMo2 trigonal pyramids,  an edgeedge with one O(2)Ho3Fe tetrahedra,  an edgeedge with one O(3)Ho3Fe tetrahedra,  an edgeedge with one O(4)Ho3Mo tetrahedra,  an edgeedge with one O(7)HoFe2Mo trigonal pyramid,  an edgeedge with one O(5)HoFeMo2 trigonal pyramid, and  an edgeedge with one O(6)HoFeMo2 trigonal pyramid. In the second O site, O(2) is bonded to one Ho(1), one Ho(2), one Ho(4), and one Fe(1) atom to form OHo3Fe tetrahedra that share corners with two equivalent O(3)Ho3Fe tetrahedra, corners with two equivalent O(1)Ho3Mo tetrahedra, corners with two equivalent O(4)Ho3Mo tetrahedra, corners with four equivalent O(2)Ho3Fe tetrahedra, corners with two equivalent O(7)HoFe2Mo trigonal pyramids, corners with two equivalent O(6)HoFeMo2 trigonal pyramids,  an edgeedge with one O(3)Ho3Fe tetrahedra,  an edgeedge with one O(1)Ho3Mo tetrahedra,  an edgeedge with one O(4)Ho3Mo tetrahedra,  an edgeedge with one O(7)HoFe2Mo trigonal pyramid, and  an edgeedge with one O(6)HoFeMo2 trigonal pyramid. In the third O site, O(3) is bonded to one Ho(2), one Ho(3), one Ho(4), and one Fe(2) atom to form OHo3Fe tetrahedra that share corners with two equivalent O(2)Ho3Fe tetrahedra, corners with two equivalent O(1)Ho3Mo tetrahedra, corners with two equivalent O(4)Ho3Mo tetrahedra, corners with four equivalent O(3)Ho3Fe tetrahedra, corners with two equivalent O(7)HoFe2Mo trigonal pyramids, corners with two equivalent O(5)HoFeMo2 trigonal pyramids,  an edgeedge with one O(2)Ho3Fe tetrahedra,  an edgeedge with one O(1)Ho3Mo tetrahedra,  an edgeedge with one O(4)Ho3Mo tetrahedra,  an edgeedge with one O(7)HoFe2Mo trigonal pyramid, and  an edgeedge with one O(5)HoFeMo2 trigonal pyramid. In the fourth O site, O(4) is bonded to one Ho(1), one Ho(3), one Ho(4), and one Mo(1) atom to form OHo3Mo tetrahedra that share corners with two equivalent O(2)Ho3Fe tetrahedra, corners with two equivalent O(3)Ho3Fe tetrahedra, corners with two equivalent O(1)Ho3Mo tetrahedra, corners with four equivalent O(4)Ho3Mo tetrahedra, corners with two equivalent O(5)HoFeMo2 trigonal pyramids, corners with two equivalent O(6)HoFeMo2 trigonal pyramids,  an edgeedge with one O(2)Ho3Fe tetrahedra,  an edgeedge with one O(3)Ho3Fe tetrahedra,  an edgeedge with one O(1)Ho3Mo tetrahedra,  an edgeedge with one O(5)HoFeMo2 trigonal pyramid, and  an edgeedge with one O(6)HoFeMo2 trigonal pyramid. In the fifth O site, O(5) is bonded to one Ho(3), one Mo(1), one Mo(2), and one Fe(2) atom to form distorted OHoFeMo2 trigonal pyramids that share corners with two equivalent O(3)Ho3Fe tetrahedra, corners with two equivalent O(1)Ho3Mo tetrahedra, corners with two equivalent O(4)Ho3Mo tetrahedra, corners with two equivalent O(7)HoFe2Mo trigonal pyramids, corners with two equivalent O(6)HoFeMo2 trigonal pyramids, corners with four equivalent O(5)HoFeMo2 trigonal pyramids,  an edgeedge with one O(3)Ho3Fe tetrahedra,  an edgeedge with one O(1)Ho3Mo tetrahedra,  an edgeedge with one O(4)Ho3Mo tetrahedra,  an edgeedge with one O(7)HoFe2Mo trigonal pyramid, and  an edgeedge with one O(6)HoFeMo2 trigonal pyramid. In the sixth O site, O(6) is bonded to one Ho(1), one Mo(1), one Mo(2), and one Fe(1) atom to form distorted OHoFeMo2 trigonal pyramids that share corners with two equivalent O(2)Ho3Fe tetrahedra, corners with two equivalent O(1)Ho3Mo tetrahedra, corners with two equivalent O(4)Ho3Mo tetrahedra, corners with two equivalent O(7)HoFe2Mo trigonal pyramids, corners with two equivalent O(5)HoFeMo2 trigonal pyramids, corners with four equivalent O(6)HoFeMo2 trigonal pyramids,  an edgeedge with one O(2)Ho3Fe tetrahedra,  an edgeedge with one O(1)Ho3Mo tetrahedra,  an edgeedge with one O(4)Ho3Mo tetrahedra,  an edgeedge with one O(7)HoFe2Mo trigonal pyramid, and  an edgeedge with one O(5)HoFeMo2 trigonal pyramid. In the seventh O site, O(7) is bonded to one Ho(2), one Mo(2), one Fe(1), and one Fe(2) atom to form distorted OHoFe2Mo trigonal pyramids that share corners with two equivalent O(2)Ho3Fe tetrahedra, corners with two equivalent O(3)Ho3Fe tetrahedra, corners with two equivalent O(1)Ho3Mo tetrahedra, corners with two equivalent O(5)HoFeMo2 trigonal pyramids, corners with two equivalent O(6)HoFeMo2 trigonal pyramids, corners with four equivalent O(7)HoFe2Mo trigonal pyramids,  an edgeedge with one O(2)Ho3Fe tetrahedra,  an edgeedge with one O(3)Ho3Fe tetrahedra,  an edgeedge with one O(1)Ho3Mo tetrahedra,  an edgeedge with one O(5)HoFeMo2 trigonal pyramid, and  an edgeedge with one O(6)HoFeMo2 trigonal pyramid.
Ho2MoFeO7 crystallizes in the triclinic P-1 space group. There are four inequivalent Ho sites. In the first Ho site, Ho(1) is bonded in a body-centered cubic geometry to two equivalent O(1), two equivalent O(2), two equivalent O(4), and two equivalent O(6) atoms. Both Ho(1)-O(1) bond lengths are 2.26 Å. Both Ho(1)-O(2) bond lengths are 2.36 Å. Both Ho(1)-O(4) bond lengths are 2.36 Å. Both Ho(1)-O(6) bond lengths are 2.57 Å. In the second Ho site, Ho(2) is bonded in a body-centered cubic geometry to two equivalent O(1), two equivalent O(2), two equivalent O(3), and two equivalent O(7) atoms. Both Ho(2)-O(1) bond lengths are 2.36 Å. Both Ho(2)-O(2) bond lengths are 2.33 Å. Both Ho(2)-O(3) bond lengths are 2.35 Å. Both Ho(2)-O(7) bond lengths are 2.61 Å. In the third Ho site, Ho(3) is bonded in a body-centered cubic geometry to two equivalent O(1), two equivalent O(3), two equivalent O(4), and two equivalent O(5) atoms. Both Ho(3)-O(1) bond lengths are 2.28 Å. Both Ho(3)-O(3) bond lengths are 2.35 Å. Both Ho(3)-O(4) bond lengths are 2.38 Å. Both Ho(3)-O(5) bond lengths are 2.54 Å. In the fourth Ho site, Ho(4) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms to form distorted HoO6 octahedra that share corners with two equivalent Mo(1)O6 octahedra, corners with two equivalent Fe(1)O6 octahedra, and corners with two equivalent Fe(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 61-63°. Both Ho(4)-O(2) bond lengths are 2.23 Å. Both Ho(4)-O(3) bond lengths are 2.26 Å. Both Ho(4)-O(4) bond lengths are 2.21 Å. There are two inequivalent Mo sites. In the first Mo site, Mo(1) is bonded to two equivalent O(4), two equivalent O(5), and two equivalent O(6) atoms to form MoO6 octahedra that share corners with two equivalent Ho(4)O6 octahedra, corners with two equivalent Fe(1)O6 octahedra, corners with two equivalent Fe(2)O6 octahedra, and edges with two equivalent Mo(2)O8 hexagonal bipyramids. The corner-sharing octahedral tilt angles range from 49-61°. Both Mo(1)-O(4) bond lengths are 1.97 Å. Both Mo(1)-O(5) bond lengths are 1.99 Å. Both Mo(1)-O(6) bond lengths are 2.00 Å. In the second Mo site, Mo(2) is bonded to two equivalent O(1), two equivalent O(5), two equivalent O(6), and two equivalent O(7) atoms to form distorted MoO8 hexagonal bipyramids that share edges with two equivalent Mo(1)O6 octahedra, edges with two equivalent Fe(1)O6 octahedra, and edges with two equivalent Fe(2)O6 octahedra. Both Mo(2)-O(1) bond lengths are 2.01 Å. Both Mo(2)-O(5) bond lengths are 2.29 Å. Both Mo(2)-O(6) bond lengths are 2.43 Å. Both Mo(2)-O(7) bond lengths are 2.18 Å. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to two equivalent O(2), two equivalent O(6), and two equivalent O(7) atoms to form distorted FeO6 octahedra that share corners with two equivalent Ho(4)O6 octahedra, corners with two equivalent Mo(1)O6 octahedra, corners with two equivalent Fe(2)O6 octahedra, and edges with two equivalent Mo(2)O8 hexagonal bipyramids. The corner-sharing octahedral tilt angles range from 49-63°. Both Fe(1)-O(2) bond lengths are 1.99 Å. Both Fe(1)-O(6) bond lengths are 2.02 Å. Both Fe(1)-O(7) bond lengths are 2.13 Å. In the second Fe site, Fe(2) is bonded to two equivalent O(3), two equivalent O(5), and two equivalent O(7) atoms to form distorted FeO6 octahedra that share corners with two equivalent Ho(4)O6 octahedra, corners with two equivalent Mo(1)O6 octahedra, corners with two equivalent Fe(1)O6 octahedra, and edges with two equivalent Mo(2)O8 hexagonal bipyramids. The corner-sharing octahedral tilt angles range from 56-63°. Both Fe(2)-O(3) bond lengths are 1.95 Å. Both Fe(2)-O(5) bond lengths are 2.16 Å. Both Fe(2)-O(7) bond lengths are 2.09 Å. There are seven inequivalent O sites. In the first O site, O(1) is bonded to one Ho(1), one Ho(2), one Ho(3), and one Mo(2) atom to form OHo3Mo tetrahedra that share corners with two equivalent O(2)Ho3Fe tetrahedra, corners with two equivalent O(3)Ho3Fe tetrahedra, corners with two equivalent O(4)Ho3Mo tetrahedra, corners with four equivalent O(1)Ho3Mo tetrahedra, corners with two equivalent O(7)HoFe2Mo trigonal pyramids, corners with two equivalent O(5)HoFeMo2 trigonal pyramids, corners with two equivalent O(6)HoFeMo2 trigonal pyramids,  an edgeedge with one O(2)Ho3Fe tetrahedra,  an edgeedge with one O(3)Ho3Fe tetrahedra,  an edgeedge with one O(4)Ho3Mo tetrahedra,  an edgeedge with one O(7)HoFe2Mo trigonal pyramid,  an edgeedge with one O(5)HoFeMo2 trigonal pyramid, and  an edgeedge with one O(6)HoFeMo2 trigonal pyramid. In the second O site, O(2) is bonded to one Ho(1), one Ho(2), one Ho(4), and one Fe(1) atom to form OHo3Fe tetrahedra that share corners with two equivalent O(3)Ho3Fe tetrahedra, corners with two equivalent O(1)Ho3Mo tetrahedra, corners with two equivalent O(4)Ho3Mo tetrahedra, corners with four equivalent O(2)Ho3Fe tetrahedra, corners with two equivalent O(7)HoFe2Mo trigonal pyramids, corners with two equivalent O(6)HoFeMo2 trigonal pyramids,  an edgeedge with one O(3)Ho3Fe tetrahedra,  an edgeedge with one O(1)Ho3Mo tetrahedra,  an edgeedge with one O(4)Ho3Mo tetrahedra,  an edgeedge with one O(7)HoFe2Mo trigonal pyramid, and  an edgeedge with one O(6)HoFeMo2 trigonal pyramid. In the third O site, O(3) is bonded to one Ho(2), one Ho(3), one Ho(4), and one Fe(2) atom to form OHo3Fe tetrahedra that share corners with two equivalent O(2)Ho3Fe tetrahedra, corners with two equivalent O(1)Ho3Mo tetrahedra, corners with two equivalent O(4)Ho3Mo tetrahedra, corners with four equivalent O(3)Ho3Fe tetrahedra, corners with two equivalent O(7)HoFe2Mo trigonal pyramids, corners with two equivalent O(5)HoFeMo2 trigonal pyramids,  an edgeedge with one O(2)Ho3Fe tetrahedra,  an edgeedge with one O(1)Ho3Mo tetrahedra,  an edgeedge with one O(4)Ho3Mo tetrahedra,  an edgeedge with one O(7)HoFe2Mo trigonal pyramid, and  an edgeedge with one O(5)HoFeMo2 trigonal pyramid. In the fourth O site, O(4) is bonded to one Ho(1), one Ho(3), one Ho(4), and one Mo(1) atom to form OHo3Mo tetrahedra that share corners with two equivalent O(2)Ho3Fe tetrahedra, corners with two equivalent O(3)Ho3Fe tetrahedra, corners with two equivalent O(1)Ho3Mo tetrahedra, corners with four equivalent O(4)Ho3Mo tetrahedra, corners with two equivalent O(5)HoFeMo2 trigonal pyramids, corners with two equivalent O(6)HoFeMo2 trigonal pyramids,  an edgeedge with one O(2)Ho3Fe tetrahedra,  an edgeedge with one O(3)Ho3Fe tetrahedra,  an edgeedge with one O(1)Ho3Mo tetrahedra,  an edgeedge with one O(5)HoFeMo2 trigonal pyramid, and  an edgeedge with one O(6)HoFeMo2 trigonal pyramid. In the fifth O site, O(5) is bonded to one Ho(3), one Mo(1), one Mo(2), and one Fe(2) atom to form distorted OHoFeMo2 trigonal pyramids that share corners with two equivalent O(3)Ho3Fe tetrahedra, corners with two equivalent O(1)Ho3Mo tetrahedra, corners with two equivalent O(4)Ho3Mo tetrahedra, corners with two equivalent O(7)HoFe2Mo trigonal pyramids, corners with two equivalent O(6)HoFeMo2 trigonal pyramids, corners with four equivalent O(5)HoFeMo2 trigonal pyramids,  an edgeedge with one O(3)Ho3Fe tetrahedra,  an edgeedge with one O(1)Ho3Mo tetrahedra,  an edgeedge with one O(4)Ho3Mo tetrahedra,  an edgeedge with one O(7)HoFe2Mo trigonal pyramid, and  an edgeedge with one O(6)HoFeMo2 trigonal pyramid. In the sixth O site, O(6) is bonded to one Ho(1), one Mo(1), one Mo(2), and one Fe(1) atom to form distorted OHoFeMo2 trigonal pyramids that share corners with two equivalent O(2)Ho3Fe tetrahedra, corners with two equivalent O(1)Ho3Mo tetrahedra, corners with two equivalent O(4)Ho3Mo tetrahedra, corners with two equivalent O(7)HoFe2Mo trigonal pyramids, corners with two equivalent O(5)HoFeMo2 trigonal pyramids, corners with four equivalent O(6)HoFeMo2 trigonal pyramids,  an edgeedge with one O(2)Ho3Fe tetrahedra,  an edgeedge with one O(1)Ho3Mo tetrahedra,  an edgeedge with one O(4)Ho3Mo tetrahedra,  an edgeedge with one O(7)HoFe2Mo trigonal pyramid, and  an edgeedge with one O(5)HoFeMo2 trigonal pyramid. In the seventh O site, O(7) is bonded to one Ho(2), one Mo(2), one Fe(1), and one Fe(2) atom to form distorted OHoFe2Mo trigonal pyramids that share corners with two equivalent O(2)Ho3Fe tetrahedra, corners with two equivalent O(3)Ho3Fe tetrahedra, corners with two equivalent O(1)Ho3Mo tetrahedra, corners with two equivalent O(5)HoFeMo2 trigonal pyramids, corners with two equivalent O(6)HoFeMo2 trigonal pyramids, corners with four equivalent O(7)HoFe2Mo trigonal pyramids,  an edgeedge with one O(2)Ho3Fe tetrahedra,  an edgeedge with one O(3)Ho3Fe tetrahedra,  an edgeedge with one O(1)Ho3Mo tetrahedra,  an edgeedge with one O(5)HoFeMo2 trigonal pyramid, and  an edgeedge with one O(6)HoFeMo2 trigonal pyramid.