The structure described by Li2Hf2O5 crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded in a distorted see-saw-like geometry to one O(5) and three equivalent O(1) atoms. In the second Li site, Li(2) is bonded in a 5-coordinate geometry to one O(1), one O(3), and three equivalent O(5) atoms. There are two inequivalent Hf sites. In the first Hf site, Hf(1) is bonded in a 6-coordinate geometry to one O(1), one O(3), one O(4), and three equivalent O(2) atoms. In the second Hf site, Hf(2) is bonded in a 6-coordinate geometry to one O(2), one O(5), two equivalent O(3), and two equivalent O(4) atoms. There are five inequivalent O sites. In the first O site, O(1) is bonded to one Li(2), three equivalent Li(1), and one Hf(1) atom to form distorted OLi4Hf trigonal bipyramids that share corners with two equivalent O(1)Li4Hf trigonal bipyramids, corners with two equivalent O(5)Li4Hf trigonal bipyramids, corners with three equivalent O(2)Hf4 trigonal pyramids, edges with two equivalent O(1)Li4Hf trigonal bipyramids, and edges with two equivalent O(5)Li4Hf trigonal bipyramids. In the second O site, O(2) is bonded to one Hf(2) and three equivalent Hf(1) atoms to form distorted OHf4 trigonal pyramids that share  a cornercorner with one O(5)Li4Hf trigonal bipyramid, corners with three equivalent O(1)Li4Hf trigonal bipyramids, corners with two equivalent O(2)Hf4 trigonal pyramids, and edges with two equivalent O(2)Hf4 trigonal pyramids. In the third O site, O(3) is bonded in a 4-coordinate geometry to one Li(2), one Hf(1), and two equivalent Hf(2) atoms. In the fourth O site, O(4) is bonded in a distorted trigonal non-coplanar geometry to one Hf(1) and two equivalent Hf(2) atoms. In the fifth O site, O(5) is bonded to one Li(1), three equivalent Li(2), and one Hf(2) atom to form OLi4Hf trigonal bipyramids that share corners with two equivalent O(1)Li4Hf trigonal bipyramids, corners with two equivalent O(5)Li4Hf trigonal bipyramids,  a cornercorner with one O(2)Hf4 trigonal pyramid, edges with two equivalent O(1)Li4Hf trigonal bipyramids, and edges with two equivalent O(5)Li4Hf trigonal bipyramids. is represented by the CIF file [CIF]
data_Li2Hf2O5
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.896
_cell_length_b   10.265
_cell_length_c   12.947
_cell_angle_alpha   57.273
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   435.603
_cell_formula_units_Z   4
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
loop_
 _atom_site_type_symbol
 _atom_site_label
 _atom_site_symmetry_multiplicity
 _atom_site_fract_x
 _atom_site_fract_y
 _atom_site_fract_z
 _atom_site_occupancy
  Li  Li0  1  0.260  0.049  0.046  1.0
  Li  Li1  1  0.299  0.925  0.328  1.0
  Li  Li2  1  0.799  0.075  0.172  1.0
  Li  Li3  1  0.760  0.951  0.454  1.0
  Li  Li4  1  0.240  0.049  0.546  1.0
  Li  Li5  1  0.201  0.925  0.828  1.0
  Li  Li6  1  0.701  0.075  0.672  1.0
  Li  Li7  1  0.740  0.951  0.954  1.0
  Hf  Hf8  1  0.678  0.331  0.853  1.0
  Hf  Hf9  1  0.868  0.666  0.366  1.0
  Hf  Hf10  1  0.178  0.669  0.647  1.0
  Hf  Hf11  1  0.632  0.666  0.866  1.0
  Hf  Hf12  1  0.368  0.334  0.134  1.0
  Hf  Hf13  1  0.822  0.331  0.353  1.0
  Hf  Hf14  1  0.132  0.334  0.634  1.0
  Hf  Hf15  1  0.322  0.669  0.147  1.0
  O  O16  1  0.746  0.119  0.983  1.0
  O  O17  1  0.169  0.384  0.787  1.0
  O  O18  1  0.347  0.699  0.298  1.0
  O  O19  1  0.118  0.586  0.535  1.0
  O  O20  1  0.618  0.414  0.965  1.0
  O  O21  1  0.807  0.874  0.337  1.0
  O  O22  1  0.669  0.616  0.713  1.0
  O  O23  1  0.246  0.881  0.517  1.0
  O  O24  1  0.307  0.126  0.163  1.0
  O  O25  1  0.153  0.699  0.798  1.0
  O  O26  1  0.847  0.301  0.202  1.0
  O  O27  1  0.693  0.874  0.837  1.0
  O  O28  1  0.754  0.119  0.483  1.0
  O  O29  1  0.331  0.384  0.287  1.0
  O  O30  1  0.193  0.126  0.663  1.0
  O  O31  1  0.382  0.586  0.035  1.0
  O  O32  1  0.882  0.414  0.465  1.0
  O  O33  1  0.653  0.301  0.702  1.0
  O  O34  1  0.831  0.616  0.213  1.0
  O  O35  1  0.254  0.881  0.017  1.0
[/CIF]
.
The structure described by Li2Hf2O5 crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded in a distorted see-saw-like geometry to one O(5) and three equivalent O(1) atoms. In the second Li site, Li(2) is bonded in a 5-coordinate geometry to one O(1), one O(3), and three equivalent O(5) atoms. There are two inequivalent Hf sites. In the first Hf site, Hf(1) is bonded in a 6-coordinate geometry to one O(1), one O(3), one O(4), and three equivalent O(2) atoms. In the second Hf site, Hf(2) is bonded in a 6-coordinate geometry to one O(2), one O(5), two equivalent O(3), and two equivalent O(4) atoms. There are five inequivalent O sites. In the first O site, O(1) is bonded to one Li(2), three equivalent Li(1), and one Hf(1) atom to form distorted OLi4Hf trigonal bipyramids that share corners with two equivalent O(1)Li4Hf trigonal bipyramids, corners with two equivalent O(5)Li4Hf trigonal bipyramids, corners with three equivalent O(2)Hf4 trigonal pyramids, edges with two equivalent O(1)Li4Hf trigonal bipyramids, and edges with two equivalent O(5)Li4Hf trigonal bipyramids. In the second O site, O(2) is bonded to one Hf(2) and three equivalent Hf(1) atoms to form distorted OHf4 trigonal pyramids that share  a cornercorner with one O(5)Li4Hf trigonal bipyramid, corners with three equivalent O(1)Li4Hf trigonal bipyramids, corners with two equivalent O(2)Hf4 trigonal pyramids, and edges with two equivalent O(2)Hf4 trigonal pyramids. In the third O site, O(3) is bonded in a 4-coordinate geometry to one Li(2), one Hf(1), and two equivalent Hf(2) atoms. In the fourth O site, O(4) is bonded in a distorted trigonal non-coplanar geometry to one Hf(1) and two equivalent Hf(2) atoms. In the fifth O site, O(5) is bonded to one Li(1), three equivalent Li(2), and one Hf(2) atom to form OLi4Hf trigonal bipyramids that share corners with two equivalent O(1)Li4Hf trigonal bipyramids, corners with two equivalent O(5)Li4Hf trigonal bipyramids,  a cornercorner with one O(2)Hf4 trigonal pyramid, edges with two equivalent O(1)Li4Hf trigonal bipyramids, and edges with two equivalent O(5)Li4Hf trigonal bipyramids. is represented by the CIF file [CIF]
data_Li2Hf2O5
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.896
_cell_length_b   10.265
_cell_length_c   12.947
_cell_angle_alpha   57.273
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   435.603
_cell_formula_units_Z   4
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
loop_
 _atom_site_type_symbol
 _atom_site_label
 _atom_site_symmetry_multiplicity
 _atom_site_fract_x
 _atom_site_fract_y
 _atom_site_fract_z
 _atom_site_occupancy
  Li  Li0  1  0.260  0.049  0.046  1.0
  Li  Li1  1  0.299  0.925  0.328  1.0
  Li  Li2  1  0.799  0.075  0.172  1.0
  Li  Li3  1  0.760  0.951  0.454  1.0
  Li  Li4  1  0.240  0.049  0.546  1.0
  Li  Li5  1  0.201  0.925  0.828  1.0
  Li  Li6  1  0.701  0.075  0.672  1.0
  Li  Li7  1  0.740  0.951  0.954  1.0
  Hf  Hf8  1  0.678  0.331  0.853  1.0
  Hf  Hf9  1  0.868  0.666  0.366  1.0
  Hf  Hf10  1  0.178  0.669  0.647  1.0
  Hf  Hf11  1  0.632  0.666  0.866  1.0
  Hf  Hf12  1  0.368  0.334  0.134  1.0
  Hf  Hf13  1  0.822  0.331  0.353  1.0
  Hf  Hf14  1  0.132  0.334  0.634  1.0
  Hf  Hf15  1  0.322  0.669  0.147  1.0
  O  O16  1  0.746  0.119  0.983  1.0
  O  O17  1  0.169  0.384  0.787  1.0
  O  O18  1  0.347  0.699  0.298  1.0
  O  O19  1  0.118  0.586  0.535  1.0
  O  O20  1  0.618  0.414  0.965  1.0
  O  O21  1  0.807  0.874  0.337  1.0
  O  O22  1  0.669  0.616  0.713  1.0
  O  O23  1  0.246  0.881  0.517  1.0
  O  O24  1  0.307  0.126  0.163  1.0
  O  O25  1  0.153  0.699  0.798  1.0
  O  O26  1  0.847  0.301  0.202  1.0
  O  O27  1  0.693  0.874  0.837  1.0
  O  O28  1  0.754  0.119  0.483  1.0
  O  O29  1  0.331  0.384  0.287  1.0
  O  O30  1  0.193  0.126  0.663  1.0
  O  O31  1  0.382  0.586  0.035  1.0
  O  O32  1  0.882  0.414  0.465  1.0
  O  O33  1  0.653  0.301  0.702  1.0
  O  O34  1  0.831  0.616  0.213  1.0
  O  O35  1  0.254  0.881  0.017  1.0
[/CIF]
.