The material described by MgPm2Se4 crystallizes in the orthorhombic Pnma space group. Mg(1) is bonded in a distorted trigonal pyramidal geometry to one Se(2), one Se(3), and two equivalent Se(1) atoms. There are two inequivalent Pm sites. In the first Pm site, Pm(1) is bonded in a 7-coordinate geometry to one Se(2), two equivalent Se(3), and four equivalent Se(1) atoms. In the second Pm site, Pm(2) is bonded in a 6-coordinate geometry to one Se(2), one Se(3), and four equivalent Se(1) atoms. There are three inequivalent Se sites. In the first Se site, Se(1) is bonded to one Mg(1), two equivalent Pm(1), and two equivalent Pm(2) atoms to form a mixture of distorted corner, edge, and face-sharing SePm4Mg square pyramids. In the second Se site, Se(2) is bonded in a T-shaped geometry to one Mg(1), one Pm(1), and one Pm(2) atom. In the third Se site, Se(3) is bonded in a distorted rectangular see-saw-like geometry to one Mg(1), one Pm(2), and two equivalent Pm(1) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_Pm2MgSe4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.542
_cell_length_b   8.495
_cell_length_c   12.264
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   785.788
_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
  Pm  Pm0  1  0.750  0.042  0.318  1.0
  Pm  Pm1  1  0.250  0.958  0.682  1.0
  Pm  Pm2  1  0.250  0.458  0.818  1.0
  Pm  Pm3  1  0.750  0.542  0.182  1.0
  Pm  Pm4  1  0.250  0.079  0.031  1.0
  Pm  Pm5  1  0.750  0.921  0.969  1.0
  Pm  Pm6  1  0.750  0.421  0.531  1.0
  Pm  Pm7  1  0.250  0.579  0.469  1.0
  Mg  Mg8  1  0.250  0.190  0.415  1.0
  Mg  Mg9  1  0.750  0.810  0.585  1.0
  Mg  Mg10  1  0.750  0.310  0.915  1.0
  Mg  Mg11  1  0.250  0.690  0.085  1.0
  Se  Se12  1  0.494  0.138  0.845  1.0
  Se  Se13  1  0.506  0.862  0.155  1.0
  Se  Se14  1  0.506  0.362  0.345  1.0
  Se  Se15  1  0.494  0.638  0.655  1.0
  Se  Se16  1  0.006  0.638  0.655  1.0
  Se  Se17  1  0.994  0.362  0.345  1.0
  Se  Se18  1  0.994  0.862  0.155  1.0
  Se  Se19  1  0.006  0.138  0.845  1.0
  Se  Se20  1  0.250  0.905  0.442  1.0
  Se  Se21  1  0.750  0.095  0.558  1.0
  Se  Se22  1  0.750  0.595  0.942  1.0
  Se  Se23  1  0.250  0.405  0.058  1.0
  Se  Se24  1  0.750  0.214  0.112  1.0
  Se  Se25  1  0.250  0.786  0.888  1.0
  Se  Se26  1  0.250  0.286  0.612  1.0
  Se  Se27  1  0.750  0.714  0.388  1.0
[/CIF]
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The material described by MgPm2Se4 crystallizes in the orthorhombic Pnma space group. Mg(1) is bonded in a distorted trigonal pyramidal geometry to one Se(2), one Se(3), and two equivalent Se(1) atoms. There are two inequivalent Pm sites. In the first Pm site, Pm(1) is bonded in a 7-coordinate geometry to one Se(2), two equivalent Se(3), and four equivalent Se(1) atoms. In the second Pm site, Pm(2) is bonded in a 6-coordinate geometry to one Se(2), one Se(3), and four equivalent Se(1) atoms. There are three inequivalent Se sites. In the first Se site, Se(1) is bonded to one Mg(1), two equivalent Pm(1), and two equivalent Pm(2) atoms to form a mixture of distorted corner, edge, and face-sharing SePm4Mg square pyramids. In the second Se site, Se(2) is bonded in a T-shaped geometry to one Mg(1), one Pm(1), and one Pm(2) atom. In the third Se site, Se(3) is bonded in a distorted rectangular see-saw-like geometry to one Mg(1), one Pm(2), and two equivalent Pm(1) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_Pm2MgSe4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.542
_cell_length_b   8.495
_cell_length_c   12.264
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   785.788
_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
  Pm  Pm0  1  0.750  0.042  0.318  1.0
  Pm  Pm1  1  0.250  0.958  0.682  1.0
  Pm  Pm2  1  0.250  0.458  0.818  1.0
  Pm  Pm3  1  0.750  0.542  0.182  1.0
  Pm  Pm4  1  0.250  0.079  0.031  1.0
  Pm  Pm5  1  0.750  0.921  0.969  1.0
  Pm  Pm6  1  0.750  0.421  0.531  1.0
  Pm  Pm7  1  0.250  0.579  0.469  1.0
  Mg  Mg8  1  0.250  0.190  0.415  1.0
  Mg  Mg9  1  0.750  0.810  0.585  1.0
  Mg  Mg10  1  0.750  0.310  0.915  1.0
  Mg  Mg11  1  0.250  0.690  0.085  1.0
  Se  Se12  1  0.494  0.138  0.845  1.0
  Se  Se13  1  0.506  0.862  0.155  1.0
  Se  Se14  1  0.506  0.362  0.345  1.0
  Se  Se15  1  0.494  0.638  0.655  1.0
  Se  Se16  1  0.006  0.638  0.655  1.0
  Se  Se17  1  0.994  0.362  0.345  1.0
  Se  Se18  1  0.994  0.862  0.155  1.0
  Se  Se19  1  0.006  0.138  0.845  1.0
  Se  Se20  1  0.250  0.905  0.442  1.0
  Se  Se21  1  0.750  0.095  0.558  1.0
  Se  Se22  1  0.750  0.595  0.942  1.0
  Se  Se23  1  0.250  0.405  0.058  1.0
  Se  Se24  1  0.750  0.214  0.112  1.0
  Se  Se25  1  0.250  0.786  0.888  1.0
  Se  Se26  1  0.250  0.286  0.612  1.0
  Se  Se27  1  0.750  0.714  0.388  1.0
[/CIF]
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