data_CuSe2O5
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.49
_cell_length_b   6.49
_cell_length_c   7.87
_cell_angle_alpha   110.04
_cell_angle_beta   110.04
_cell_angle_gamma   44.21
_symmetry_Int_Tables_number   1
_chemical_formula_structural   CuSe2O5
_chemical_formula_sum   'Cu2 Se4 O10'
_cell_volume   214.45
_cell_formula_units_Z   2
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
  Cu  Cu0  1  0.55  0.0  0.65  1.0
  Cu  Cu1  1  0.0  0.0  0.0  1.0
  Se  Se12  1  0.32  0.28  0.89  1.0
  Se  Se13  1  0.34  0.28  0.08  1.0
  Se  Se14  1  0.77  0.72  0.23  1.0
  Se  Se15  1  0.79  0.72  0.42  1.0
  O  O2  1  0.99  0.3  0.69  1.0
  O  O3  1  0.67  0.32  0.78  1.0
  O  O4  1  0.83  0.37  0.48  1.0
  O  O5  1  0.98  0.32  0.18  1.0
  O  O6  1  0.66  0.3  0.27  1.0
  O  O7  1  0.45  0.7  0.04  1.0
  O  O8  1  0.13  0.68  0.13  1.0
  O  O9  1  0.28  0.63  0.83  1.0
  O  O10  1  0.44  0.68  0.53  1.0
  O  O11  1  0.12  0.7  0.61  1.0

data_CuSe2O5
_symmetry_space_group_name_H-M   P1
_cell_length_a   4.88
_cell_length_b   6.49
_cell_length_c   7.87
_cell_angle_alpha   110.04
_cell_angle_beta   90.0
_cell_angle_gamma   112.1
_symmetry_Int_Tables_number   1
_chemical_formula_structural   CuSe2O5
_chemical_formula_sum   'Cu2 Se4 O10'
_cell_volume   214.45
_cell_formula_units_Z   2
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
  Cu  Cu0  1  0.0  0.0  0.0  1.0
  Cu  Cu1  1  0.0  0.45  0.35  1.0
  Se  Se2  1  0.28  0.49  0.58  1.0
  Se  Se3  1  0.28  0.51  0.77  1.0
  Se  Se4  1  0.72  0.38  0.92  1.0
  Se  Se5  1  0.72  0.4  0.11  1.0
  O  O6  1  0.3  0.19  0.39  1.0
  O  O7  1  0.3  0.86  0.96  1.0
  O  O8  1  0.32  0.2  0.87  1.0
  O  O9  1  0.32  0.88  0.47  1.0
  O  O10  1  0.37  0.09  0.17  1.0
  O  O11  1  0.63  0.8  0.52  1.0
  O  O12  1  0.68  0.0  0.22  1.0
  O  O13  1  0.68  0.69  0.82  1.0
  O  O14  1  0.7  0.03  0.73  1.0
  O  O15  1  0.7  0.7  0.31  1.0

Cu Cu Se Se Se Se O O O O O O O O O O
Cu Cu Se Se Se Se O O O O O O O O O O 0 14 o - o 0 2 o o o 0 6 - o o 0 5 o - o 0 7 o o o 1 12 o - o 1 7 - o - 1 11 o - o 1 13 o - - 1 9 - o o 2 3 o o + 3 12 o o o 4 5 o o o 4 9 o o o 4 11 o o o 6 8 o o o 7 13 o o o 8 10 o o o 8 14 o o o 11 13 o o - 13 15 o o o 
CuSe2O5 crystallizes in the triclinic P1 space group. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded in a 4-coordinate geometry to one Se(1), one Se(4), one O(1), one O(2), and one O(9) atom. The Cu(1)-Se(1) bond length is 2.13 Å. The Cu(1)-Se(4) bond length is 2.19 Å. The Cu(1)-O(1) bond length is 2.65 Å. The Cu(1)-O(2) bond length is 2.56 Å. The Cu(1)-O(9) bond length is 2.46 Å. In the second Cu site, Cu(2) is bonded in a 5-coordinate geometry to one O(2), one O(4), one O(5), one O(6), one O(7), and one O(8) atom. The Cu(2)-O(2) bond length is 2.33 Å. The Cu(2)-O(4) bond length is 2.04 Å. The Cu(2)-O(5) bond length is 2.70 Å. The Cu(2)-O(6) bond length is 2.01 Å. The Cu(2)-O(7) bond length is 2.13 Å. The Cu(2)-O(8) bond length is 2.04 Å. There are four inequivalent Se sites. In the first Se site, Se(1) is bonded in a 5-coordinate geometry to one Cu(1), one Se(2), one O(1), one O(7), and one O(8) atom. The Se(1)-Se(2) bond length is 1.45 Å. The Se(1)-O(1) bond length is 2.07 Å. The Se(1)-O(7) bond length is 2.33 Å. The Se(1)-O(8) bond length is 2.27 Å. In the second Se site, Se(2) is bonded in a 4-coordinate geometry to one Se(1), one O(4), one O(5), and one O(7) atom. The Se(2)-O(4) bond length is 2.51 Å. The Se(2)-O(5) bond length is 2.19 Å. The Se(2)-O(7) bond length is 1.78 Å. In the third Se site, Se(3) is bonded in a 4-coordinate geometry to one Se(4), one O(4), one O(6), and one O(7) atom. The Se(3)-Se(4) bond length is 1.45 Å. The Se(3)-O(4) bond length is 1.78 Å. The Se(3)-O(6) bond length is 2.19 Å. The Se(3)-O(7) bond length is 2.51 Å. In the fourth Se site, Se(4) is bonded in a 5-coordinate geometry to one Cu(1), one Se(3), one O(10), one O(3), and one O(4) atom. The Se(4)-O(10) bond length is 2.07 Å. The Se(4)-O(3) bond length is 2.27 Å. The Se(4)-O(4) bond length is 2.33 Å. There are ten inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Cu(1), one Se(1), and one O(3) atom. The O(1)-O(3) bond length is 1.65 Å. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Cu(1), one Cu(2), and one O(8) atom. The O(2)-O(8) bond length is 1.84 Å. In the third O site, O(3) is bonded in a distorted trigonal pyramidal geometry to one Se(4), one O(1), one O(5), and one O(9) atom. The O(3)-O(5) bond length is 1.76 Å. The O(3)-O(9) bond length is 1.84 Å. In the fourth O site, O(4) is bonded in a distorted bent 150 degrees geometry to one Cu(2), one Se(2), one Se(3), and one Se(4) atom. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to one Cu(2), one Se(2), and one O(3) atom. In the sixth O site, O(6) is bonded in a 3-coordinate geometry to one Cu(2), one Se(3), and one O(8) atom. The O(6)-O(8) bond length is 1.76 Å. In the seventh O site, O(7) is bonded in a 2-coordinate geometry to one Cu(2), one Se(1), one Se(2), and one Se(3) atom. In the eighth O site, O(8) is bonded in a 5-coordinate geometry to one Cu(2), one Se(1), one O(10), one O(2), and one O(6) atom. The O(8)-O(10) bond length is 1.65 Å. In the ninth O site, O(9) is bonded in an L-shaped geometry to one Cu(1) and one O(3) atom. In the tenth O site, O(10) is bonded in a distorted bent 150 degrees geometry to one Se(4) and one O(8) atom.