The crystal structure described by Mg2SmH7 crystallizes in the tetragonal P4_12_12 space group. Mg(1) is bonded in a 7-coordinate geometry to one H(1), two equivalent H(2), two equivalent H(3), and two equivalent H(4) atoms. Sm(1) is bonded to four equivalent H(1), four equivalent H(2), and four equivalent H(3) atoms to form distorted face-sharing SmH12 cuboctahedra. There are four inequivalent H sites. In the first H site, H(4) is bonded to four equivalent Mg(1) atoms to form HMg4 tetrahedra that share corners with four equivalent H(4)Mg4 tetrahedra, corners with four equivalent H(2)Sm2Mg2 tetrahedra, and edges with two equivalent H(2)Sm2Mg2 tetrahedra. In the second H site, H(1) is bonded in a 3-coordinate geometry to one Mg(1) and two equivalent Sm(1) atoms. In the third H site, H(2) is bonded to two equivalent Mg(1) and two equivalent Sm(1) atoms to form HSm2Mg2 tetrahedra that share corners with two equivalent H(4)Mg4 tetrahedra, corners with four equivalent H(2)Sm2Mg2 tetrahedra,  an edgeedge with one H(4)Mg4 tetrahedra, and edges with two equivalent H(2)Sm2Mg2 tetrahedra. In the fourth H site, H(3) is bonded in a 4-coordinate geometry to two equivalent Mg(1) and two equivalent Sm(1) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_SmMg2H7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.218
_cell_length_b   6.218
_cell_length_c   9.352
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   361.587
_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
  Sm  Sm0  1  0.771  0.229  0.750  1.0
  Sm  Sm1  1  0.229  0.771  0.250  1.0
  Sm  Sm2  1  0.729  0.729  0.500  1.0
  Sm  Sm3  1  0.271  0.271  0.000  1.0
  Mg  Mg4  1  0.532  0.240  0.400  1.0
  Mg  Mg5  1  0.468  0.760  0.900  1.0
  Mg  Mg6  1  0.740  0.968  0.150  1.0
  Mg  Mg7  1  0.260  0.032  0.650  1.0
  Mg  Mg8  1  0.760  0.468  0.100  1.0
  Mg  Mg9  1  0.240  0.532  0.600  1.0
  Mg  Mg10  1  0.968  0.740  0.850  1.0
  Mg  Mg11  1  0.032  0.260  0.350  1.0
  H  H12  1  0.540  0.477  0.623  1.0
  H  H13  1  0.460  0.523  0.123  1.0
  H  H14  1  0.977  0.960  0.373  1.0
  H  H15  1  0.023  0.040  0.873  1.0
  H  H16  1  0.523  0.460  0.877  1.0
  H  H17  1  0.477  0.540  0.377  1.0
  H  H18  1  0.960  0.977  0.627  1.0
  H  H19  1  0.040  0.023  0.127  1.0
  H  H20  1  0.579  0.067  0.572  1.0
  H  H21  1  0.421  0.933  0.072  1.0
  H  H22  1  0.567  0.921  0.322  1.0
  H  H23  1  0.433  0.079  0.822  1.0
  H  H24  1  0.933  0.421  0.928  1.0
  H  H25  1  0.067  0.579  0.428  1.0
  H  H26  1  0.921  0.567  0.678  1.0
  H  H27  1  0.079  0.433  0.178  1.0
  H  H28  1  0.813  0.346  0.498  1.0
  H  H29  1  0.187  0.654  0.998  1.0
  H  H30  1  0.846  0.687  0.248  1.0
  H  H31  1  0.154  0.313  0.748  1.0
  H  H32  1  0.654  0.187  0.002  1.0
  H  H33  1  0.346  0.813  0.502  1.0
  H  H34  1  0.687  0.846  0.752  1.0
  H  H35  1  0.313  0.154  0.252  1.0
  H  H36  1  0.252  0.748  0.750  1.0
  H  H37  1  0.748  0.252  0.250  1.0
  H  H38  1  0.248  0.248  0.500  1.0
  H  H39  1  0.752  0.752  0.000  1.0
[/CIF]
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The crystal structure described by Mg2SmH7 crystallizes in the tetragonal P4_12_12 space group. Mg(1) is bonded in a 7-coordinate geometry to one H(1), two equivalent H(2), two equivalent H(3), and two equivalent H(4) atoms. Sm(1) is bonded to four equivalent H(1), four equivalent H(2), and four equivalent H(3) atoms to form distorted face-sharing SmH12 cuboctahedra. There are four inequivalent H sites. In the first H site, H(4) is bonded to four equivalent Mg(1) atoms to form HMg4 tetrahedra that share corners with four equivalent H(4)Mg4 tetrahedra, corners with four equivalent H(2)Sm2Mg2 tetrahedra, and edges with two equivalent H(2)Sm2Mg2 tetrahedra. In the second H site, H(1) is bonded in a 3-coordinate geometry to one Mg(1) and two equivalent Sm(1) atoms. In the third H site, H(2) is bonded to two equivalent Mg(1) and two equivalent Sm(1) atoms to form HSm2Mg2 tetrahedra that share corners with two equivalent H(4)Mg4 tetrahedra, corners with four equivalent H(2)Sm2Mg2 tetrahedra,  an edgeedge with one H(4)Mg4 tetrahedra, and edges with two equivalent H(2)Sm2Mg2 tetrahedra. In the fourth H site, H(3) is bonded in a 4-coordinate geometry to two equivalent Mg(1) and two equivalent Sm(1) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_SmMg2H7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.218
_cell_length_b   6.218
_cell_length_c   9.352
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   361.587
_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
  Sm  Sm0  1  0.771  0.229  0.750  1.0
  Sm  Sm1  1  0.229  0.771  0.250  1.0
  Sm  Sm2  1  0.729  0.729  0.500  1.0
  Sm  Sm3  1  0.271  0.271  0.000  1.0
  Mg  Mg4  1  0.532  0.240  0.400  1.0
  Mg  Mg5  1  0.468  0.760  0.900  1.0
  Mg  Mg6  1  0.740  0.968  0.150  1.0
  Mg  Mg7  1  0.260  0.032  0.650  1.0
  Mg  Mg8  1  0.760  0.468  0.100  1.0
  Mg  Mg9  1  0.240  0.532  0.600  1.0
  Mg  Mg10  1  0.968  0.740  0.850  1.0
  Mg  Mg11  1  0.032  0.260  0.350  1.0
  H  H12  1  0.540  0.477  0.623  1.0
  H  H13  1  0.460  0.523  0.123  1.0
  H  H14  1  0.977  0.960  0.373  1.0
  H  H15  1  0.023  0.040  0.873  1.0
  H  H16  1  0.523  0.460  0.877  1.0
  H  H17  1  0.477  0.540  0.377  1.0
  H  H18  1  0.960  0.977  0.627  1.0
  H  H19  1  0.040  0.023  0.127  1.0
  H  H20  1  0.579  0.067  0.572  1.0
  H  H21  1  0.421  0.933  0.072  1.0
  H  H22  1  0.567  0.921  0.322  1.0
  H  H23  1  0.433  0.079  0.822  1.0
  H  H24  1  0.933  0.421  0.928  1.0
  H  H25  1  0.067  0.579  0.428  1.0
  H  H26  1  0.921  0.567  0.678  1.0
  H  H27  1  0.079  0.433  0.178  1.0
  H  H28  1  0.813  0.346  0.498  1.0
  H  H29  1  0.187  0.654  0.998  1.0
  H  H30  1  0.846  0.687  0.248  1.0
  H  H31  1  0.154  0.313  0.748  1.0
  H  H32  1  0.654  0.187  0.002  1.0
  H  H33  1  0.346  0.813  0.502  1.0
  H  H34  1  0.687  0.846  0.752  1.0
  H  H35  1  0.313  0.154  0.252  1.0
  H  H36  1  0.252  0.748  0.750  1.0
  H  H37  1  0.748  0.252  0.250  1.0
  H  H38  1  0.248  0.248  0.500  1.0
  H  H39  1  0.752  0.752  0.000  1.0
[/CIF]
.