The crystal structure described by Eu2GeSe4 crystallizes in the monoclinic P2_1 space group. There are two inequivalent Eu sites. In the first Eu site, Eu(1) is bonded in a 7-coordinate geometry to one Se(2), two equivalent Se(1), two equivalent Se(3), and two equivalent Se(4) atoms. In the second Eu site, Eu(2) is bonded to one Se(3), two equivalent Se(1), two equivalent Se(2), and two equivalent Se(4) atoms to form distorted EuSe7 pentagonal bipyramids that share corners with two equivalent Eu(2)Se7 pentagonal bipyramids, corners with three equivalent Ge(1)Se4 tetrahedra, edges with two equivalent Eu(2)Se7 pentagonal bipyramids, and edges with two equivalent Ge(1)Se4 tetrahedra. 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 three equivalent Eu(2)Se7 pentagonal bipyramids and edges with two equivalent Eu(2)Se7 pentagonal bipyramids. There are four inequivalent Se sites. In the first Se site, Se(1) is bonded to two equivalent Eu(1), two equivalent Eu(2), and one Ge(1) atom to form a mixture of distorted corner, edge, and face-sharing SeEu4Ge square pyramids. In the second Se site, Se(2) is bonded in a distorted see-saw-like geometry to one Eu(1), two equivalent Eu(2), and one Ge(1) atom. In the third Se site, Se(3) is bonded in a distorted see-saw-like geometry to one Eu(2), two equivalent Eu(1), and one Ge(1) atom. In the fourth Se site, Se(4) is bonded to two equivalent Eu(1), two equivalent Eu(2), and one Ge(1) atom to form a mixture of corner, edge, and face-sharing SeEu4Ge square pyramids. is represented by the CIF file [CIF]
data_Eu2GeSe4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.131
_cell_length_b   6.977
_cell_length_c   8.349
_cell_angle_alpha   72.213
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   395.572
_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
  Eu  Eu0  1  0.278  0.226  0.444  1.0
  Eu  Eu1  1  0.294  0.251  0.937  1.0
  Eu  Eu2  1  0.778  0.774  0.556  1.0
  Eu  Eu3  1  0.794  0.749  0.063  1.0
  Ge  Ge4  1  0.752  0.233  0.695  1.0
  Ge  Ge5  1  0.252  0.767  0.305  1.0
  Se  Se6  1  0.524  0.981  0.250  1.0
  Se  Se7  1  0.717  0.428  0.886  1.0
  Se  Se8  1  0.024  0.019  0.750  1.0
  Se  Se9  1  0.702  0.420  0.405  1.0
  Se  Se10  1  0.510  0.983  0.762  1.0
  Se  Se11  1  0.217  0.572  0.114  1.0
  Se  Se12  1  0.202  0.580  0.595  1.0
  Se  Se13  1  0.010  0.017  0.238  1.0
[/CIF]
.
The crystal structure described by Eu2GeSe4 crystallizes in the monoclinic P2_1 space group. There are two inequivalent Eu sites. In the first Eu site, Eu(1) is bonded in a 7-coordinate geometry to one Se(2), two equivalent Se(1), two equivalent Se(3), and two equivalent Se(4) atoms. In the second Eu site, Eu(2) is bonded to one Se(3), two equivalent Se(1), two equivalent Se(2), and two equivalent Se(4) atoms to form distorted EuSe7 pentagonal bipyramids that share corners with two equivalent Eu(2)Se7 pentagonal bipyramids, corners with three equivalent Ge(1)Se4 tetrahedra, edges with two equivalent Eu(2)Se7 pentagonal bipyramids, and edges with two equivalent Ge(1)Se4 tetrahedra. 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 three equivalent Eu(2)Se7 pentagonal bipyramids and edges with two equivalent Eu(2)Se7 pentagonal bipyramids. There are four inequivalent Se sites. In the first Se site, Se(1) is bonded to two equivalent Eu(1), two equivalent Eu(2), and one Ge(1) atom to form a mixture of distorted corner, edge, and face-sharing SeEu4Ge square pyramids. In the second Se site, Se(2) is bonded in a distorted see-saw-like geometry to one Eu(1), two equivalent Eu(2), and one Ge(1) atom. In the third Se site, Se(3) is bonded in a distorted see-saw-like geometry to one Eu(2), two equivalent Eu(1), and one Ge(1) atom. In the fourth Se site, Se(4) is bonded to two equivalent Eu(1), two equivalent Eu(2), and one Ge(1) atom to form a mixture of corner, edge, and face-sharing SeEu4Ge square pyramids. is represented by the CIF file [CIF]
data_Eu2GeSe4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.131
_cell_length_b   6.977
_cell_length_c   8.349
_cell_angle_alpha   72.213
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   395.572
_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
  Eu  Eu0  1  0.278  0.226  0.444  1.0
  Eu  Eu1  1  0.294  0.251  0.937  1.0
  Eu  Eu2  1  0.778  0.774  0.556  1.0
  Eu  Eu3  1  0.794  0.749  0.063  1.0
  Ge  Ge4  1  0.752  0.233  0.695  1.0
  Ge  Ge5  1  0.252  0.767  0.305  1.0
  Se  Se6  1  0.524  0.981  0.250  1.0
  Se  Se7  1  0.717  0.428  0.886  1.0
  Se  Se8  1  0.024  0.019  0.750  1.0
  Se  Se9  1  0.702  0.420  0.405  1.0
  Se  Se10  1  0.510  0.983  0.762  1.0
  Se  Se11  1  0.217  0.572  0.114  1.0
  Se  Se12  1  0.202  0.580  0.595  1.0
  Se  Se13  1  0.010  0.017  0.238  1.0
[/CIF]
.