The compound described by MgPm3 is beta Cu3Ti-like structured and crystallizes in the tetragonal I4/mmm space group. Mg(1) is bonded to four equivalent Pm(1) and eight equivalent Pm(2) atoms to form MgPm12 cuboctahedra that share corners with four equivalent Mg(1)Pm12 cuboctahedra, corners with eight equivalent Pm(1)Pm8Mg4 cuboctahedra, edges with eight equivalent Mg(1)Pm12 cuboctahedra, edges with sixteen equivalent Pm(2)Pm8Mg4 cuboctahedra, faces with four equivalent Mg(1)Pm12 cuboctahedra, faces with six equivalent Pm(1)Pm8Mg4 cuboctahedra, and faces with eight equivalent Pm(2)Pm8Mg4 cuboctahedra. There are two inequivalent Pm sites. In the first Pm site, Pm(1) is bonded to four equivalent Mg(1) and eight equivalent Pm(2) atoms to form PmPm8Mg4 cuboctahedra that share corners with four equivalent Pm(1)Pm8Mg4 cuboctahedra, corners with eight equivalent Mg(1)Pm12 cuboctahedra, edges with eight equivalent Pm(1)Pm8Mg4 cuboctahedra, edges with sixteen equivalent Pm(2)Pm8Mg4 cuboctahedra, faces with four equivalent Pm(1)Pm8Mg4 cuboctahedra, faces with six equivalent Mg(1)Pm12 cuboctahedra, and faces with eight equivalent Pm(2)Pm8Mg4 cuboctahedra. In the second Pm site, Pm(2) is bonded to four equivalent Mg(1), four equivalent Pm(1), and four equivalent Pm(2) atoms to form PmPm8Mg4 cuboctahedra that share corners with twelve equivalent Pm(2)Pm8Mg4 cuboctahedra, edges with eight equivalent Mg(1)Pm12 cuboctahedra, edges with eight equivalent Pm(1)Pm8Mg4 cuboctahedra, edges with eight equivalent Pm(2)Pm8Mg4 cuboctahedra, faces with four equivalent Mg(1)Pm12 cuboctahedra, faces with four equivalent Pm(1)Pm8Mg4 cuboctahedra, and faces with ten equivalent Pm(2)Pm8Mg4 cuboctahedra. is represented by the CIF file [CIF]
data_Pm3Mg
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.136
_cell_length_b   6.136
_cell_length_c   6.136
_cell_angle_alpha   132.028
_cell_angle_beta   132.028
_cell_angle_gamma   70.185
_symmetry_Int_Tables_number   1
_cell_volume   124.958
_cell_formula_units_Z   1
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  0.500  0.500  0.000  1.0
  Pm  Pm1  1  0.750  0.250  0.500  1.0
  Pm  Pm2  1  0.250  0.750  0.500  1.0
  Mg  Mg3  1  0.000  0.000  0.000  1.0
[/CIF]
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The compound described by MgPm3 is beta Cu3Ti-like structured and crystallizes in the tetragonal I4/mmm space group. Mg(1) is bonded to four equivalent Pm(1) and eight equivalent Pm(2) atoms to form MgPm12 cuboctahedra that share corners with four equivalent Mg(1)Pm12 cuboctahedra, corners with eight equivalent Pm(1)Pm8Mg4 cuboctahedra, edges with eight equivalent Mg(1)Pm12 cuboctahedra, edges with sixteen equivalent Pm(2)Pm8Mg4 cuboctahedra, faces with four equivalent Mg(1)Pm12 cuboctahedra, faces with six equivalent Pm(1)Pm8Mg4 cuboctahedra, and faces with eight equivalent Pm(2)Pm8Mg4 cuboctahedra. There are two inequivalent Pm sites. In the first Pm site, Pm(1) is bonded to four equivalent Mg(1) and eight equivalent Pm(2) atoms to form PmPm8Mg4 cuboctahedra that share corners with four equivalent Pm(1)Pm8Mg4 cuboctahedra, corners with eight equivalent Mg(1)Pm12 cuboctahedra, edges with eight equivalent Pm(1)Pm8Mg4 cuboctahedra, edges with sixteen equivalent Pm(2)Pm8Mg4 cuboctahedra, faces with four equivalent Pm(1)Pm8Mg4 cuboctahedra, faces with six equivalent Mg(1)Pm12 cuboctahedra, and faces with eight equivalent Pm(2)Pm8Mg4 cuboctahedra. In the second Pm site, Pm(2) is bonded to four equivalent Mg(1), four equivalent Pm(1), and four equivalent Pm(2) atoms to form PmPm8Mg4 cuboctahedra that share corners with twelve equivalent Pm(2)Pm8Mg4 cuboctahedra, edges with eight equivalent Mg(1)Pm12 cuboctahedra, edges with eight equivalent Pm(1)Pm8Mg4 cuboctahedra, edges with eight equivalent Pm(2)Pm8Mg4 cuboctahedra, faces with four equivalent Mg(1)Pm12 cuboctahedra, faces with four equivalent Pm(1)Pm8Mg4 cuboctahedra, and faces with ten equivalent Pm(2)Pm8Mg4 cuboctahedra. is represented by the CIF file [CIF]
data_Pm3Mg
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.136
_cell_length_b   6.136
_cell_length_c   6.136
_cell_angle_alpha   132.028
_cell_angle_beta   132.028
_cell_angle_gamma   70.185
_symmetry_Int_Tables_number   1
_cell_volume   124.958
_cell_formula_units_Z   1
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  0.500  0.500  0.000  1.0
  Pm  Pm1  1  0.750  0.250  0.500  1.0
  Pm  Pm2  1  0.250  0.750  0.500  1.0
  Mg  Mg3  1  0.000  0.000  0.000  1.0
[/CIF]
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