The compound described by Eu2Mg3H10 crystallizes in the monoclinic C2/m space group. There are three inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to two equivalent H(2), two equivalent H(4), and two equivalent H(5) atoms to form MgH6 octahedra that share corners with two equivalent Mg(2)H6 octahedra, corners with two equivalent Mg(3)H6 octahedra, edges with two equivalent Eu(1)H12 cuboctahedra, and edges with two equivalent Mg(1)H6 octahedra. The corner-sharing octahedral tilt angles range from 52-60°. In the second Mg site, Mg(2) is bonded to one H(1), one H(6), two equivalent H(2), and two equivalent H(7) atoms to form MgH6 octahedra that share  a cornercorner with one Mg(3)H6 octahedra, corners with two equivalent Mg(1)H6 octahedra, corners with two equivalent Mg(2)H6 octahedra, and faces with three equivalent Eu(1)H12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-60°. In the third Mg site, Mg(3) is bonded to one H(1), one H(4), two equivalent H(3), and two equivalent H(8) atoms to form MgH6 octahedra that share corners with two equivalent Eu(1)H12 cuboctahedra,  a cornercorner with one Mg(2)H6 octahedra, corners with two equivalent Mg(1)H6 octahedra,  an edgeedge with one Mg(3)H6 octahedra, and faces with two equivalent Eu(1)H12 cuboctahedra. The corner-sharing octahedral tilt angles range from 9-52°. There are two inequivalent Eu sites. In the first Eu site, Eu(1) is bonded to one H(5), one H(6), two equivalent H(1), two equivalent H(2), two equivalent H(3), two equivalent H(7), and two equivalent H(8) atoms to form distorted EuH12 cuboctahedra that share corners with four equivalent Eu(1)H12 cuboctahedra, corners with two equivalent Mg(3)H6 octahedra,  an edgeedge with one Eu(1)H12 cuboctahedra, edges with two equivalent Mg(1)H6 octahedra, faces with two equivalent Mg(3)H6 octahedra, and faces with three equivalent Mg(2)H6 octahedra. The corner-sharing octahedral tilt angles are 47°. In the second Eu site, Eu(2) is bonded in a 12-coordinate geometry to one H(1), two equivalent H(2), two equivalent H(7), three equivalent H(6), and four equivalent H(8) atoms. There are eight inequivalent H sites. In the first H site, H(6) is bonded in a distorted single-bond geometry to one Mg(2), one Eu(1), and three equivalent Eu(2) atoms. In the second H site, H(7) is bonded in a linear geometry to two equivalent Mg(2), two equivalent Eu(1), and two equivalent Eu(2) atoms. In the third H site, H(8) is bonded to one Mg(3), one Eu(1), and two equivalent Eu(2) atoms to form a mixture of distorted edge and corner-sharing HEu3Mg tetrahedra. In the fourth H site, H(1) is bonded in a distorted linear geometry to one Mg(2), one Mg(3), one Eu(2), and two equivalent Eu(1) atoms. In the fifth H site, H(2) is bonded in a distorted bent 120 degrees geometry to one Mg(1), one Mg(2), one Eu(1), and one Eu(2) atom. In the sixth H site, H(3) is bonded in a 4-coordinate geometry to two equivalent Mg(3) and two equivalent Eu(1) atoms. In the seventh H site, H(4) is bonded in a trigonal planar geometry to one Mg(3) and two equivalent Mg(1) atoms. In the eighth H site, H(5) is bonded in a distorted L-shaped geometry to two equivalent Mg(1) and one Eu(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Eu2Mg3H10
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.126
_cell_length_b   9.126
_cell_length_c   7.304
_cell_angle_alpha   69.951
_cell_angle_beta   69.951
_cell_angle_gamma   36.027
_symmetry_Int_Tables_number   1
_cell_volume   333.780
_cell_formula_units_Z   2
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
  Eu  Eu0  1  0.617  0.617  0.278  1.0
  Eu  Eu1  1  0.383  0.383  0.722  1.0
  Eu  Eu2  1  0.721  0.721  0.684  1.0
  Eu  Eu3  1  0.279  0.279  0.316  1.0
  Mg  Mg4  1  0.741  0.259  0.000  1.0
  Mg  Mg5  1  0.259  0.741  0.000  1.0
  Mg  Mg6  1  0.825  0.825  0.022  1.0
  Mg  Mg7  1  0.175  0.175  0.978  1.0
  Mg  Mg8  1  0.924  0.924  0.447  1.0
  Mg  Mg9  1  0.076  0.076  0.553  1.0
  H  H10  1  0.864  0.864  0.740  1.0
  H  H11  1  0.136  0.136  0.260  1.0
  H  H12  1  0.607  0.164  0.029  1.0
  H  H13  1  0.393  0.836  0.971  1.0
  H  H14  1  0.836  0.393  0.971  1.0
  H  H15  1  0.164  0.607  0.029  1.0
  H  H16  1  0.762  0.238  0.500  1.0
  H  H17  1  0.238  0.762  0.500  1.0
  H  H18  1  0.980  0.980  0.177  1.0
  H  H19  1  0.020  0.020  0.823  1.0
  H  H20  1  0.484  0.484  0.196  1.0
  H  H21  1  0.516  0.516  0.804  1.0
  H  H22  1  0.760  0.760  0.297  1.0
  H  H23  1  0.240  0.240  0.703  1.0
  H  H24  1  0.500  0.000  0.000  1.0
  H  H25  1  0.000  0.500  0.000  1.0
  H  H26  1  0.596  0.093  0.484  1.0
  H  H27  1  0.404  0.907  0.516  1.0
  H  H28  1  0.907  0.404  0.516  1.0
  H  H29  1  0.093  0.596  0.484  1.0
[/CIF]
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The compound described by Eu2Mg3H10 crystallizes in the monoclinic C2/m space group. There are three inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to two equivalent H(2), two equivalent H(4), and two equivalent H(5) atoms to form MgH6 octahedra that share corners with two equivalent Mg(2)H6 octahedra, corners with two equivalent Mg(3)H6 octahedra, edges with two equivalent Eu(1)H12 cuboctahedra, and edges with two equivalent Mg(1)H6 octahedra. The corner-sharing octahedral tilt angles range from 52-60°. In the second Mg site, Mg(2) is bonded to one H(1), one H(6), two equivalent H(2), and two equivalent H(7) atoms to form MgH6 octahedra that share  a cornercorner with one Mg(3)H6 octahedra, corners with two equivalent Mg(1)H6 octahedra, corners with two equivalent Mg(2)H6 octahedra, and faces with three equivalent Eu(1)H12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-60°. In the third Mg site, Mg(3) is bonded to one H(1), one H(4), two equivalent H(3), and two equivalent H(8) atoms to form MgH6 octahedra that share corners with two equivalent Eu(1)H12 cuboctahedra,  a cornercorner with one Mg(2)H6 octahedra, corners with two equivalent Mg(1)H6 octahedra,  an edgeedge with one Mg(3)H6 octahedra, and faces with two equivalent Eu(1)H12 cuboctahedra. The corner-sharing octahedral tilt angles range from 9-52°. There are two inequivalent Eu sites. In the first Eu site, Eu(1) is bonded to one H(5), one H(6), two equivalent H(1), two equivalent H(2), two equivalent H(3), two equivalent H(7), and two equivalent H(8) atoms to form distorted EuH12 cuboctahedra that share corners with four equivalent Eu(1)H12 cuboctahedra, corners with two equivalent Mg(3)H6 octahedra,  an edgeedge with one Eu(1)H12 cuboctahedra, edges with two equivalent Mg(1)H6 octahedra, faces with two equivalent Mg(3)H6 octahedra, and faces with three equivalent Mg(2)H6 octahedra. The corner-sharing octahedral tilt angles are 47°. In the second Eu site, Eu(2) is bonded in a 12-coordinate geometry to one H(1), two equivalent H(2), two equivalent H(7), three equivalent H(6), and four equivalent H(8) atoms. There are eight inequivalent H sites. In the first H site, H(6) is bonded in a distorted single-bond geometry to one Mg(2), one Eu(1), and three equivalent Eu(2) atoms. In the second H site, H(7) is bonded in a linear geometry to two equivalent Mg(2), two equivalent Eu(1), and two equivalent Eu(2) atoms. In the third H site, H(8) is bonded to one Mg(3), one Eu(1), and two equivalent Eu(2) atoms to form a mixture of distorted edge and corner-sharing HEu3Mg tetrahedra. In the fourth H site, H(1) is bonded in a distorted linear geometry to one Mg(2), one Mg(3), one Eu(2), and two equivalent Eu(1) atoms. In the fifth H site, H(2) is bonded in a distorted bent 120 degrees geometry to one Mg(1), one Mg(2), one Eu(1), and one Eu(2) atom. In the sixth H site, H(3) is bonded in a 4-coordinate geometry to two equivalent Mg(3) and two equivalent Eu(1) atoms. In the seventh H site, H(4) is bonded in a trigonal planar geometry to one Mg(3) and two equivalent Mg(1) atoms. In the eighth H site, H(5) is bonded in a distorted L-shaped geometry to two equivalent Mg(1) and one Eu(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Eu2Mg3H10
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.126
_cell_length_b   9.126
_cell_length_c   7.304
_cell_angle_alpha   69.951
_cell_angle_beta   69.951
_cell_angle_gamma   36.027
_symmetry_Int_Tables_number   1
_cell_volume   333.780
_cell_formula_units_Z   2
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
  Eu  Eu0  1  0.617  0.617  0.278  1.0
  Eu  Eu1  1  0.383  0.383  0.722  1.0
  Eu  Eu2  1  0.721  0.721  0.684  1.0
  Eu  Eu3  1  0.279  0.279  0.316  1.0
  Mg  Mg4  1  0.741  0.259  0.000  1.0
  Mg  Mg5  1  0.259  0.741  0.000  1.0
  Mg  Mg6  1  0.825  0.825  0.022  1.0
  Mg  Mg7  1  0.175  0.175  0.978  1.0
  Mg  Mg8  1  0.924  0.924  0.447  1.0
  Mg  Mg9  1  0.076  0.076  0.553  1.0
  H  H10  1  0.864  0.864  0.740  1.0
  H  H11  1  0.136  0.136  0.260  1.0
  H  H12  1  0.607  0.164  0.029  1.0
  H  H13  1  0.393  0.836  0.971  1.0
  H  H14  1  0.836  0.393  0.971  1.0
  H  H15  1  0.164  0.607  0.029  1.0
  H  H16  1  0.762  0.238  0.500  1.0
  H  H17  1  0.238  0.762  0.500  1.0
  H  H18  1  0.980  0.980  0.177  1.0
  H  H19  1  0.020  0.020  0.823  1.0
  H  H20  1  0.484  0.484  0.196  1.0
  H  H21  1  0.516  0.516  0.804  1.0
  H  H22  1  0.760  0.760  0.297  1.0
  H  H23  1  0.240  0.240  0.703  1.0
  H  H24  1  0.500  0.000  0.000  1.0
  H  H25  1  0.000  0.500  0.000  1.0
  H  H26  1  0.596  0.093  0.484  1.0
  H  H27  1  0.404  0.907  0.516  1.0
  H  H28  1  0.907  0.404  0.516  1.0
  H  H29  1  0.093  0.596  0.484  1.0
[/CIF]
.