The material structure described by K2MgH4 is (La,Ba)CuO4 structured and crystallizes in the tetragonal I4/mmm space group. K(1) is bonded in a distorted q6 geometry to four equivalent H(1) and five equivalent H(2) atoms. Mg(1) is bonded to two equivalent H(2) and four equivalent H(1) atoms to form corner-sharing MgH6 octahedra. The corner-sharing octahedra are not tilted. There are two inequivalent H sites. In the first H site, H(2) is bonded to five equivalent K(1) and one Mg(1) atom to form distorted HK5Mg octahedra that share corners with five equivalent H(2)K5Mg octahedra, corners with twelve equivalent H(1)K4Mg2 octahedra, edges with eight equivalent H(2)K5Mg octahedra, and faces with four equivalent H(1)K4Mg2 octahedra. The corner-sharing octahedral tilt angles range from 0-59°. In the second H site, H(1) is bonded to four equivalent K(1) and two equivalent Mg(1) atoms to form distorted HK4Mg2 octahedra that share corners with two equivalent H(1)K4Mg2 octahedra, corners with twelve equivalent H(2)K5Mg octahedra, edges with two equivalent H(1)K4Mg2 octahedra, faces with four equivalent H(1)K4Mg2 octahedra, and faces with four equivalent H(2)K5Mg octahedra. The corner-sharing octahedral tilt angles range from 0-59°. is represented by the Crystallographic Information File (CIF) [CIF]
data_K2MgH4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.009
_cell_length_b   4.009
_cell_length_c   7.345
_cell_angle_alpha   105.836
_cell_angle_beta   105.836
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   108.908
_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
  K  K0  1  0.644  0.644  0.288  1.0
  K  K1  1  0.356  0.356  0.712  1.0
  Mg  Mg2  1  0.000  0.000  0.000  1.0
  H  H3  1  0.500  0.000  0.000  1.0
  H  H4  1  0.000  0.500  0.000  1.0
  H  H5  1  0.852  0.852  0.704  1.0
  H  H6  1  0.148  0.148  0.296  1.0
[/CIF]
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The material structure described by K2MgH4 is (La,Ba)CuO4 structured and crystallizes in the tetragonal I4/mmm space group. K(1) is bonded in a distorted q6 geometry to four equivalent H(1) and five equivalent H(2) atoms. Mg(1) is bonded to two equivalent H(2) and four equivalent H(1) atoms to form corner-sharing MgH6 octahedra. The corner-sharing octahedra are not tilted. There are two inequivalent H sites. In the first H site, H(2) is bonded to five equivalent K(1) and one Mg(1) atom to form distorted HK5Mg octahedra that share corners with five equivalent H(2)K5Mg octahedra, corners with twelve equivalent H(1)K4Mg2 octahedra, edges with eight equivalent H(2)K5Mg octahedra, and faces with four equivalent H(1)K4Mg2 octahedra. The corner-sharing octahedral tilt angles range from 0-59°. In the second H site, H(1) is bonded to four equivalent K(1) and two equivalent Mg(1) atoms to form distorted HK4Mg2 octahedra that share corners with two equivalent H(1)K4Mg2 octahedra, corners with twelve equivalent H(2)K5Mg octahedra, edges with two equivalent H(1)K4Mg2 octahedra, faces with four equivalent H(1)K4Mg2 octahedra, and faces with four equivalent H(2)K5Mg octahedra. The corner-sharing octahedral tilt angles range from 0-59°. is represented by the Crystallographic Information File (CIF) [CIF]
data_K2MgH4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.009
_cell_length_b   4.009
_cell_length_c   7.345
_cell_angle_alpha   105.836
_cell_angle_beta   105.836
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   108.908
_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
  K  K0  1  0.644  0.644  0.288  1.0
  K  K1  1  0.356  0.356  0.712  1.0
  Mg  Mg2  1  0.000  0.000  0.000  1.0
  H  H3  1  0.500  0.000  0.000  1.0
  H  H4  1  0.000  0.500  0.000  1.0
  H  H5  1  0.852  0.852  0.704  1.0
  H  H6  1  0.148  0.148  0.296  1.0
[/CIF]
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