The material described by CsMgH3 crystallizes in the trigonal R-3m space group. There are two inequivalent Cs sites. In the first Cs site, Cs(1) is bonded to six equivalent H(1) and six equivalent H(2) atoms to form CsH12 cuboctahedra that share corners with six equivalent Cs(1)H12 cuboctahedra, corners with six equivalent Mg(1)H6 octahedra, faces with eight equivalent Cs(2)H12 cuboctahedra, and faces with six equivalent Mg(2)H6 octahedra. The corner-sharing octahedral tilt angles are 7°. In the second Cs site, Cs(2) is bonded to three equivalent H(1) and nine equivalent H(2) atoms to form distorted CsH12 cuboctahedra that share corners with nine equivalent Cs(2)H12 cuboctahedra, corners with three equivalent Mg(2)H6 octahedra, faces with three equivalent Cs(2)H12 cuboctahedra, faces with four equivalent Cs(1)H12 cuboctahedra, faces with three equivalent Mg(1)H6 octahedra, and faces with four equivalent Mg(2)H6 octahedra. The corner-sharing octahedral tilt angles are 5°. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to six equivalent H(2) atoms to form MgH6 octahedra that share corners with six equivalent Cs(1)H12 cuboctahedra, faces with six equivalent Cs(2)H12 cuboctahedra, and faces with two equivalent Mg(2)H6 octahedra. In the second Mg site, Mg(2) is bonded to three equivalent H(1) and three equivalent H(2) atoms to form MgH6 octahedra that share corners with three equivalent Cs(2)H12 cuboctahedra, corners with three equivalent Mg(2)H6 octahedra, faces with three equivalent Cs(1)H12 cuboctahedra, faces with four equivalent Cs(2)H12 cuboctahedra, and  a faceface with one Mg(1)H6 octahedra. The corner-sharing octahedra are not tilted. There are two inequivalent H sites. In the first H site, H(1) is bonded in a distorted linear geometry to two equivalent Cs(1), two equivalent Cs(2), and two equivalent Mg(2) atoms. In the second H site, H(2) is bonded in a distorted L-shaped geometry to one Cs(1), three equivalent Cs(2), one Mg(1), and one Mg(2) atom. is represented by the CIF file [CIF]
data_CsMgH3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.248
_cell_length_b   8.248
_cell_length_c   8.248
_cell_angle_alpha   44.393
_cell_angle_beta   44.393
_cell_angle_gamma   44.393
_symmetry_Int_Tables_number   1
_cell_volume   249.585
_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
  Cs  Cs0  1  0.000  0.000  0.000  1.0
  Cs  Cs1  1  0.787  0.787  0.787  1.0
  Cs  Cs2  1  0.213  0.213  0.213  1.0
  Mg  Mg3  1  0.500  0.500  0.500  1.0
  Mg  Mg4  1  0.621  0.621  0.621  1.0
  Mg  Mg5  1  0.379  0.379  0.379  1.0
  H  H6  1  0.500  0.000  0.500  1.0
  H  H7  1  0.000  0.500  0.500  1.0
  H  H8  1  0.500  0.500  0.000  1.0
  H  H9  1  0.305  0.713  0.305  1.0
  H  H10  1  0.713  0.305  0.305  1.0
  H  H11  1  0.305  0.305  0.713  1.0
  H  H12  1  0.695  0.695  0.287  1.0
  H  H13  1  0.287  0.695  0.695  1.0
  H  H14  1  0.695  0.287  0.695  1.0
[/CIF]
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The material described by CsMgH3 crystallizes in the trigonal R-3m space group. There are two inequivalent Cs sites. In the first Cs site, Cs(1) is bonded to six equivalent H(1) and six equivalent H(2) atoms to form CsH12 cuboctahedra that share corners with six equivalent Cs(1)H12 cuboctahedra, corners with six equivalent Mg(1)H6 octahedra, faces with eight equivalent Cs(2)H12 cuboctahedra, and faces with six equivalent Mg(2)H6 octahedra. The corner-sharing octahedral tilt angles are 7°. In the second Cs site, Cs(2) is bonded to three equivalent H(1) and nine equivalent H(2) atoms to form distorted CsH12 cuboctahedra that share corners with nine equivalent Cs(2)H12 cuboctahedra, corners with three equivalent Mg(2)H6 octahedra, faces with three equivalent Cs(2)H12 cuboctahedra, faces with four equivalent Cs(1)H12 cuboctahedra, faces with three equivalent Mg(1)H6 octahedra, and faces with four equivalent Mg(2)H6 octahedra. The corner-sharing octahedral tilt angles are 5°. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to six equivalent H(2) atoms to form MgH6 octahedra that share corners with six equivalent Cs(1)H12 cuboctahedra, faces with six equivalent Cs(2)H12 cuboctahedra, and faces with two equivalent Mg(2)H6 octahedra. In the second Mg site, Mg(2) is bonded to three equivalent H(1) and three equivalent H(2) atoms to form MgH6 octahedra that share corners with three equivalent Cs(2)H12 cuboctahedra, corners with three equivalent Mg(2)H6 octahedra, faces with three equivalent Cs(1)H12 cuboctahedra, faces with four equivalent Cs(2)H12 cuboctahedra, and  a faceface with one Mg(1)H6 octahedra. The corner-sharing octahedra are not tilted. There are two inequivalent H sites. In the first H site, H(1) is bonded in a distorted linear geometry to two equivalent Cs(1), two equivalent Cs(2), and two equivalent Mg(2) atoms. In the second H site, H(2) is bonded in a distorted L-shaped geometry to one Cs(1), three equivalent Cs(2), one Mg(1), and one Mg(2) atom. is represented by the CIF file [CIF]
data_CsMgH3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.248
_cell_length_b   8.248
_cell_length_c   8.248
_cell_angle_alpha   44.393
_cell_angle_beta   44.393
_cell_angle_gamma   44.393
_symmetry_Int_Tables_number   1
_cell_volume   249.585
_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
  Cs  Cs0  1  0.000  0.000  0.000  1.0
  Cs  Cs1  1  0.787  0.787  0.787  1.0
  Cs  Cs2  1  0.213  0.213  0.213  1.0
  Mg  Mg3  1  0.500  0.500  0.500  1.0
  Mg  Mg4  1  0.621  0.621  0.621  1.0
  Mg  Mg5  1  0.379  0.379  0.379  1.0
  H  H6  1  0.500  0.000  0.500  1.0
  H  H7  1  0.000  0.500  0.500  1.0
  H  H8  1  0.500  0.500  0.000  1.0
  H  H9  1  0.305  0.713  0.305  1.0
  H  H10  1  0.713  0.305  0.305  1.0
  H  H11  1  0.305  0.305  0.713  1.0
  H  H12  1  0.695  0.695  0.287  1.0
  H  H13  1  0.287  0.695  0.695  1.0
  H  H14  1  0.695  0.287  0.695  1.0
[/CIF]
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