The compound described by Cu2GeSe3 is Enargite-like structured and crystallizes in the triclinic P1 space group. There are four inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to one Se(1), one Se(2), one Se(4), and one Se(6) atom to form CuSe4 tetrahedra that share corners with two equivalent Cu(3)Se4 tetrahedra, corners with two equivalent Cu(4)Se4 tetrahedra, corners with two equivalent Ge(2)Se4 tetrahedra, corners with three equivalent Cu(2)Se4 tetrahedra, and corners with three equivalent Ge(1)Se4 tetrahedra. In the second Cu site, Cu(2) is bonded to one Se(1), one Se(2), one Se(4), and one Se(5) atom to form CuSe4 tetrahedra that share corners with two equivalent Cu(3)Se4 tetrahedra, corners with two equivalent Cu(4)Se4 tetrahedra, corners with two equivalent Ge(2)Se4 tetrahedra, corners with three equivalent Cu(1)Se4 tetrahedra, and corners with three equivalent Ge(1)Se4 tetrahedra. In the third Cu site, Cu(3) is bonded to one Se(1), one Se(3), one Se(5), and one Se(6) atom to form CuSe4 tetrahedra that share corners with two equivalent Cu(1)Se4 tetrahedra, corners with two equivalent Cu(2)Se4 tetrahedra, corners with two equivalent Ge(1)Se4 tetrahedra, corners with three equivalent Cu(4)Se4 tetrahedra, and corners with three equivalent Ge(2)Se4 tetrahedra. In the fourth Cu site, Cu(4) is bonded to one Se(2), one Se(3), one Se(5), and one Se(6) atom to form CuSe4 tetrahedra that share corners with two equivalent Cu(1)Se4 tetrahedra, corners with two equivalent Cu(2)Se4 tetrahedra, corners with two equivalent Ge(1)Se4 tetrahedra, corners with three equivalent Cu(3)Se4 tetrahedra, and corners with three equivalent Ge(2)Se4 tetrahedra. There are two inequivalent Ge sites. In the first Ge site, Ge(1) is bonded to one Se(1), one Se(2), one Se(3), and one Se(4) atom to form GeSe4 tetrahedra that share corners with two equivalent Cu(3)Se4 tetrahedra, corners with two equivalent Cu(4)Se4 tetrahedra, corners with two equivalent Ge(2)Se4 tetrahedra, corners with three equivalent Cu(1)Se4 tetrahedra, and corners with three equivalent Cu(2)Se4 tetrahedra. In the second Ge site, Ge(2) is bonded to one Se(3), one Se(4), one Se(5), and one Se(6) atom to form GeSe4 tetrahedra that share corners with two equivalent Cu(1)Se4 tetrahedra, corners with two equivalent Cu(2)Se4 tetrahedra, corners with two equivalent Ge(1)Se4 tetrahedra, corners with three equivalent Cu(3)Se4 tetrahedra, and corners with three equivalent Cu(4)Se4 tetrahedra. There are six inequivalent Se sites. In the first Se site, Se(1) is bonded to one Cu(1), one Cu(2), one Cu(3), and one Ge(1) atom to form SeCu3Ge tetrahedra that share corners with two equivalent Se(3)Cu2Ge2 tetrahedra, corners with two equivalent Se(5)Cu3Ge tetrahedra, corners with two equivalent Se(6)Cu3Ge tetrahedra, corners with three equivalent Se(4)Cu2Ge2 tetrahedra, and corners with three equivalent Se(2)Cu3Ge tetrahedra. In the second Se site, Se(2) is bonded to one Cu(1), one Cu(2), one Cu(4), and one Ge(1) atom to form SeCu3Ge tetrahedra that share corners with two equivalent Se(3)Cu2Ge2 tetrahedra, corners with two equivalent Se(5)Cu3Ge tetrahedra, corners with two equivalent Se(6)Cu3Ge tetrahedra, corners with three equivalent Se(4)Cu2Ge2 tetrahedra, and corners with three equivalent Se(1)Cu3Ge tetrahedra. In the third Se site, Se(3) is bonded to one Cu(3), one Cu(4), one Ge(1), and one Ge(2) atom to form SeCu2Ge2 tetrahedra that share corners with two equivalent Se(4)Cu2Ge2 tetrahedra, corners with two equivalent Se(1)Cu3Ge tetrahedra, corners with two equivalent Se(2)Cu3Ge tetrahedra, corners with three equivalent Se(5)Cu3Ge tetrahedra, and corners with three equivalent Se(6)Cu3Ge tetrahedra. In the fourth Se site, Se(4) is bonded to one Cu(1), one Cu(2), one Ge(1), and one Ge(2) atom to form SeCu2Ge2 tetrahedra that share corners with two equivalent Se(3)Cu2Ge2 tetrahedra, corners with two equivalent Se(5)Cu3Ge tetrahedra, corners with two equivalent Se(6)Cu3Ge tetrahedra, corners with three equivalent Se(1)Cu3Ge tetrahedra, and corners with three equivalent Se(2)Cu3Ge tetrahedra. In the fifth Se site, Se(5) is bonded to one Cu(2), one Cu(3), one Cu(4), and one Ge(2) atom to form SeCu3Ge tetrahedra that share corners with two equivalent Se(4)Cu2Ge2 tetrahedra, corners with two equivalent Se(1)Cu3Ge tetrahedra, corners with two equivalent Se(2)Cu3Ge tetrahedra, corners with three equivalent Se(3)Cu2Ge2 tetrahedra, and corners with three equivalent Se(6)Cu3Ge tetrahedra. In the sixth Se site, Se(6) is bonded to one Cu(1), one Cu(3), one Cu(4), and one Ge(2) atom to form SeCu3Ge tetrahedra that share corners with two equivalent Se(4)Cu2Ge2 tetrahedra, corners with two equivalent Se(1)Cu3Ge tetrahedra, corners with two equivalent Se(2)Cu3Ge tetrahedra, corners with three equivalent Se(3)Cu2Ge2 tetrahedra, and corners with three equivalent Se(5)Cu3Ge tetrahedra. is represented by the CIF file [CIF]
data_Cu2GeSe3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.881
_cell_length_b   11.767
_cell_length_c   6.786
_cell_angle_alpha   30.134
_cell_angle_beta   54.875
_cell_angle_gamma   60.162
_symmetry_Int_Tables_number   1
_cell_volume   258.421
_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  0.992  0.997  0.997  1.0
  Cu  Cu1  1  0.994  0.669  0.999  1.0
  Cu  Cu2  1  0.493  0.335  0.991  1.0
  Cu  Cu3  1  0.494  0.665  0.007  1.0
  Ge  Ge4  1  0.011  0.340  0.987  1.0
  Ge  Ge5  1  0.512  0.993  0.007  1.0
  Se  Se6  1  0.121  0.335  0.254  1.0
  Se  Se7  1  0.124  0.665  0.248  1.0
  Se  Se8  1  0.623  0.337  0.236  1.0
  Se  Se9  1  0.123  0.996  0.248  1.0
  Se  Se10  1  0.624  0.667  0.246  1.0
  Se  Se11  1  0.621  0.998  0.261  1.0
[/CIF]
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The compound described by Cu2GeSe3 is Enargite-like structured and crystallizes in the triclinic P1 space group. There are four inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to one Se(1), one Se(2), one Se(4), and one Se(6) atom to form CuSe4 tetrahedra that share corners with two equivalent Cu(3)Se4 tetrahedra, corners with two equivalent Cu(4)Se4 tetrahedra, corners with two equivalent Ge(2)Se4 tetrahedra, corners with three equivalent Cu(2)Se4 tetrahedra, and corners with three equivalent Ge(1)Se4 tetrahedra. In the second Cu site, Cu(2) is bonded to one Se(1), one Se(2), one Se(4), and one Se(5) atom to form CuSe4 tetrahedra that share corners with two equivalent Cu(3)Se4 tetrahedra, corners with two equivalent Cu(4)Se4 tetrahedra, corners with two equivalent Ge(2)Se4 tetrahedra, corners with three equivalent Cu(1)Se4 tetrahedra, and corners with three equivalent Ge(1)Se4 tetrahedra. In the third Cu site, Cu(3) is bonded to one Se(1), one Se(3), one Se(5), and one Se(6) atom to form CuSe4 tetrahedra that share corners with two equivalent Cu(1)Se4 tetrahedra, corners with two equivalent Cu(2)Se4 tetrahedra, corners with two equivalent Ge(1)Se4 tetrahedra, corners with three equivalent Cu(4)Se4 tetrahedra, and corners with three equivalent Ge(2)Se4 tetrahedra. In the fourth Cu site, Cu(4) is bonded to one Se(2), one Se(3), one Se(5), and one Se(6) atom to form CuSe4 tetrahedra that share corners with two equivalent Cu(1)Se4 tetrahedra, corners with two equivalent Cu(2)Se4 tetrahedra, corners with two equivalent Ge(1)Se4 tetrahedra, corners with three equivalent Cu(3)Se4 tetrahedra, and corners with three equivalent Ge(2)Se4 tetrahedra. There are two inequivalent Ge sites. In the first Ge site, Ge(1) is bonded to one Se(1), one Se(2), one Se(3), and one Se(4) atom to form GeSe4 tetrahedra that share corners with two equivalent Cu(3)Se4 tetrahedra, corners with two equivalent Cu(4)Se4 tetrahedra, corners with two equivalent Ge(2)Se4 tetrahedra, corners with three equivalent Cu(1)Se4 tetrahedra, and corners with three equivalent Cu(2)Se4 tetrahedra. In the second Ge site, Ge(2) is bonded to one Se(3), one Se(4), one Se(5), and one Se(6) atom to form GeSe4 tetrahedra that share corners with two equivalent Cu(1)Se4 tetrahedra, corners with two equivalent Cu(2)Se4 tetrahedra, corners with two equivalent Ge(1)Se4 tetrahedra, corners with three equivalent Cu(3)Se4 tetrahedra, and corners with three equivalent Cu(4)Se4 tetrahedra. There are six inequivalent Se sites. In the first Se site, Se(1) is bonded to one Cu(1), one Cu(2), one Cu(3), and one Ge(1) atom to form SeCu3Ge tetrahedra that share corners with two equivalent Se(3)Cu2Ge2 tetrahedra, corners with two equivalent Se(5)Cu3Ge tetrahedra, corners with two equivalent Se(6)Cu3Ge tetrahedra, corners with three equivalent Se(4)Cu2Ge2 tetrahedra, and corners with three equivalent Se(2)Cu3Ge tetrahedra. In the second Se site, Se(2) is bonded to one Cu(1), one Cu(2), one Cu(4), and one Ge(1) atom to form SeCu3Ge tetrahedra that share corners with two equivalent Se(3)Cu2Ge2 tetrahedra, corners with two equivalent Se(5)Cu3Ge tetrahedra, corners with two equivalent Se(6)Cu3Ge tetrahedra, corners with three equivalent Se(4)Cu2Ge2 tetrahedra, and corners with three equivalent Se(1)Cu3Ge tetrahedra. In the third Se site, Se(3) is bonded to one Cu(3), one Cu(4), one Ge(1), and one Ge(2) atom to form SeCu2Ge2 tetrahedra that share corners with two equivalent Se(4)Cu2Ge2 tetrahedra, corners with two equivalent Se(1)Cu3Ge tetrahedra, corners with two equivalent Se(2)Cu3Ge tetrahedra, corners with three equivalent Se(5)Cu3Ge tetrahedra, and corners with three equivalent Se(6)Cu3Ge tetrahedra. In the fourth Se site, Se(4) is bonded to one Cu(1), one Cu(2), one Ge(1), and one Ge(2) atom to form SeCu2Ge2 tetrahedra that share corners with two equivalent Se(3)Cu2Ge2 tetrahedra, corners with two equivalent Se(5)Cu3Ge tetrahedra, corners with two equivalent Se(6)Cu3Ge tetrahedra, corners with three equivalent Se(1)Cu3Ge tetrahedra, and corners with three equivalent Se(2)Cu3Ge tetrahedra. In the fifth Se site, Se(5) is bonded to one Cu(2), one Cu(3), one Cu(4), and one Ge(2) atom to form SeCu3Ge tetrahedra that share corners with two equivalent Se(4)Cu2Ge2 tetrahedra, corners with two equivalent Se(1)Cu3Ge tetrahedra, corners with two equivalent Se(2)Cu3Ge tetrahedra, corners with three equivalent Se(3)Cu2Ge2 tetrahedra, and corners with three equivalent Se(6)Cu3Ge tetrahedra. In the sixth Se site, Se(6) is bonded to one Cu(1), one Cu(3), one Cu(4), and one Ge(2) atom to form SeCu3Ge tetrahedra that share corners with two equivalent Se(4)Cu2Ge2 tetrahedra, corners with two equivalent Se(1)Cu3Ge tetrahedra, corners with two equivalent Se(2)Cu3Ge tetrahedra, corners with three equivalent Se(3)Cu2Ge2 tetrahedra, and corners with three equivalent Se(5)Cu3Ge tetrahedra. is represented by the CIF file [CIF]
data_Cu2GeSe3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.881
_cell_length_b   11.767
_cell_length_c   6.786
_cell_angle_alpha   30.134
_cell_angle_beta   54.875
_cell_angle_gamma   60.162
_symmetry_Int_Tables_number   1
_cell_volume   258.421
_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  0.992  0.997  0.997  1.0
  Cu  Cu1  1  0.994  0.669  0.999  1.0
  Cu  Cu2  1  0.493  0.335  0.991  1.0
  Cu  Cu3  1  0.494  0.665  0.007  1.0
  Ge  Ge4  1  0.011  0.340  0.987  1.0
  Ge  Ge5  1  0.512  0.993  0.007  1.0
  Se  Se6  1  0.121  0.335  0.254  1.0
  Se  Se7  1  0.124  0.665  0.248  1.0
  Se  Se8  1  0.623  0.337  0.236  1.0
  Se  Se9  1  0.123  0.996  0.248  1.0
  Se  Se10  1  0.624  0.667  0.246  1.0
  Se  Se11  1  0.621  0.998  0.261  1.0
[/CIF]
.