The crystal structure described by BaCu2GeSe4 crystallizes in the trigonal P3_121 space group. Ba(1) is bonded in a 8-coordinate geometry to four equivalent Se(1) and four equivalent Se(2) atoms. Cu(1) is bonded to two equivalent Se(1) and two equivalent Se(2) atoms to form distorted CuSe4 tetrahedra that share corners with four equivalent Cu(1)Se4 tetrahedra and corners with four equivalent Ge(1)Se4 tetrahedra. Ge(1) is bonded to two equivalent Se(1) and two equivalent Se(2) atoms to form GeSe4 tetrahedra that share corners with eight equivalent Cu(1)Se4 tetrahedra. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded in a 5-coordinate geometry to two equivalent Ba(1), two equivalent Cu(1), and one Ge(1) atom. In the second Se site, Se(2) is bonded to two equivalent Ba(1), two equivalent Cu(1), and one Ge(1) atom to form a mixture of distorted edge and corner-sharing SeBa2Cu2Ge trigonal bipyramids. is represented by the CIF file [CIF]
data_BaCu2GeSe4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.597
_cell_length_b   6.597
_cell_length_c   16.405
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   618.330
_cell_formula_units_Z   3
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
  Ba  Ba0  1  0.449  0.000  0.333  1.0
  Ba  Ba1  1  0.551  0.551  0.000  1.0
  Ba  Ba2  1  0.000  0.449  0.667  1.0
  Cu  Cu3  1  0.078  0.433  0.422  1.0
  Cu  Cu4  1  0.356  0.922  0.089  1.0
  Cu  Cu5  1  0.567  0.644  0.756  1.0
  Cu  Cu6  1  0.922  0.356  0.911  1.0
  Cu  Cu7  1  0.433  0.078  0.578  1.0
  Cu  Cu8  1  0.644  0.567  0.244  1.0
  Ge  Ge9  1  0.000  0.286  0.167  1.0
  Ge  Ge10  1  0.286  0.000  0.833  1.0
  Ge  Ge11  1  0.714  0.714  0.500  1.0
  Se  Se12  1  0.532  0.041  0.949  1.0
  Se  Se13  1  0.508  0.468  0.616  1.0
  Se  Se14  1  0.959  0.492  0.282  1.0
  Se  Se15  1  0.894  0.664  0.836  1.0
  Se  Se16  1  0.230  0.336  0.831  1.0
  Se  Se17  1  0.106  0.770  0.497  1.0
  Se  Se18  1  0.770  0.106  0.503  1.0
  Se  Se19  1  0.468  0.508  0.384  1.0
  Se  Se20  1  0.336  0.230  0.169  1.0
  Se  Se21  1  0.041  0.532  0.051  1.0
  Se  Se22  1  0.492  0.959  0.718  1.0
  Se  Se23  1  0.664  0.894  0.164  1.0
[/CIF]
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The crystal structure described by BaCu2GeSe4 crystallizes in the trigonal P3_121 space group. Ba(1) is bonded in a 8-coordinate geometry to four equivalent Se(1) and four equivalent Se(2) atoms. Cu(1) is bonded to two equivalent Se(1) and two equivalent Se(2) atoms to form distorted CuSe4 tetrahedra that share corners with four equivalent Cu(1)Se4 tetrahedra and corners with four equivalent Ge(1)Se4 tetrahedra. Ge(1) is bonded to two equivalent Se(1) and two equivalent Se(2) atoms to form GeSe4 tetrahedra that share corners with eight equivalent Cu(1)Se4 tetrahedra. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded in a 5-coordinate geometry to two equivalent Ba(1), two equivalent Cu(1), and one Ge(1) atom. In the second Se site, Se(2) is bonded to two equivalent Ba(1), two equivalent Cu(1), and one Ge(1) atom to form a mixture of distorted edge and corner-sharing SeBa2Cu2Ge trigonal bipyramids. is represented by the CIF file [CIF]
data_BaCu2GeSe4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.597
_cell_length_b   6.597
_cell_length_c   16.405
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   618.330
_cell_formula_units_Z   3
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
  Ba  Ba0  1  0.449  0.000  0.333  1.0
  Ba  Ba1  1  0.551  0.551  0.000  1.0
  Ba  Ba2  1  0.000  0.449  0.667  1.0
  Cu  Cu3  1  0.078  0.433  0.422  1.0
  Cu  Cu4  1  0.356  0.922  0.089  1.0
  Cu  Cu5  1  0.567  0.644  0.756  1.0
  Cu  Cu6  1  0.922  0.356  0.911  1.0
  Cu  Cu7  1  0.433  0.078  0.578  1.0
  Cu  Cu8  1  0.644  0.567  0.244  1.0
  Ge  Ge9  1  0.000  0.286  0.167  1.0
  Ge  Ge10  1  0.286  0.000  0.833  1.0
  Ge  Ge11  1  0.714  0.714  0.500  1.0
  Se  Se12  1  0.532  0.041  0.949  1.0
  Se  Se13  1  0.508  0.468  0.616  1.0
  Se  Se14  1  0.959  0.492  0.282  1.0
  Se  Se15  1  0.894  0.664  0.836  1.0
  Se  Se16  1  0.230  0.336  0.831  1.0
  Se  Se17  1  0.106  0.770  0.497  1.0
  Se  Se18  1  0.770  0.106  0.503  1.0
  Se  Se19  1  0.468  0.508  0.384  1.0
  Se  Se20  1  0.336  0.230  0.169  1.0
  Se  Se21  1  0.041  0.532  0.051  1.0
  Se  Se22  1  0.492  0.959  0.718  1.0
  Se  Se23  1  0.664  0.894  0.164  1.0
[/CIF]
.