The compound described by La2Mg17 crystallizes in the hexagonal P6_3/mmc space group. There are four inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 12-coordinate geometry to one Mg(2), two equivalent Mg(1), two equivalent Mg(3), four equivalent Mg(4), one La(1), and two equivalent La(2) atoms. In the second Mg site, Mg(2) is bonded in a 14-coordinate geometry to one Mg(2), three equivalent Mg(1), three equivalent Mg(3), six equivalent Mg(4), and one La(1) atom. In the third Mg site, Mg(3) is bonded to two equivalent Mg(2), four equivalent Mg(1), four equivalent Mg(4), and two equivalent La(1) atoms to form a mixture of distorted edge, face, and corner-sharing MgLa2Mg10 cuboctahedra. In the fourth Mg site, Mg(4) is bonded to two equivalent Mg(2), two equivalent Mg(3), two equivalent Mg(4), four equivalent Mg(1), one La(1), and one La(2) atom to form a mixture of distorted edge, face, and corner-sharing MgLa2Mg10 cuboctahedra. There are two inequivalent La sites. In the first La site, La(1) is bonded in a 20-coordinate geometry to two equivalent Mg(2), six equivalent Mg(1), six equivalent Mg(3), and six equivalent Mg(4) atoms. In the second La site, La(2) is bonded in a 18-coordinate geometry to six equivalent Mg(4) and twelve equivalent Mg(1) atoms. is represented by the CIF file [CIF]
data_La2Mg17
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   10.312
_cell_length_b   10.312
_cell_length_c   10.153
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   934.911
_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
  La  La0  1  0.667  0.333  0.250  1.0
  La  La1  1  0.333  0.667  0.750  1.0
  La  La2  1  0.000  0.000  0.750  1.0
  La  La3  1  0.000  0.000  0.250  1.0
  Mg  Mg4  1  0.163  0.837  0.522  1.0
  Mg  Mg5  1  0.163  0.325  0.522  1.0
  Mg  Mg6  1  0.675  0.837  0.522  1.0
  Mg  Mg7  1  0.325  0.163  0.022  1.0
  Mg  Mg8  1  0.333  0.667  0.102  1.0
  Mg  Mg9  1  0.667  0.333  0.602  1.0
  Mg  Mg10  1  0.667  0.333  0.898  1.0
  Mg  Mg11  1  0.333  0.667  0.398  1.0
  Mg  Mg12  1  0.500  0.000  0.000  1.0
  Mg  Mg13  1  0.500  0.500  0.500  1.0
  Mg  Mg14  1  0.000  0.500  0.500  1.0
  Mg  Mg15  1  0.000  0.500  0.000  1.0
  Mg  Mg16  1  0.500  0.500  0.000  1.0
  Mg  Mg17  1  0.500  0.000  0.500  1.0
  Mg  Mg18  1  0.328  0.964  0.250  1.0
  Mg  Mg19  1  0.364  0.328  0.750  1.0
  Mg  Mg20  1  0.964  0.636  0.750  1.0
  Mg  Mg21  1  0.036  0.364  0.250  1.0
  Mg  Mg22  1  0.636  0.672  0.250  1.0
  Mg  Mg23  1  0.364  0.036  0.750  1.0
  Mg  Mg24  1  0.672  0.636  0.750  1.0
  Mg  Mg25  1  0.672  0.036  0.750  1.0
  Mg  Mg26  1  0.964  0.328  0.750  1.0
  Mg  Mg27  1  0.036  0.672  0.250  1.0
  Mg  Mg28  1  0.636  0.964  0.250  1.0
  Mg  Mg29  1  0.328  0.364  0.250  1.0
  Mg  Mg30  1  0.163  0.325  0.978  1.0
  Mg  Mg31  1  0.837  0.163  0.478  1.0
  Mg  Mg32  1  0.325  0.163  0.478  1.0
  Mg  Mg33  1  0.675  0.837  0.978  1.0
  Mg  Mg34  1  0.163  0.837  0.978  1.0
  Mg  Mg35  1  0.837  0.675  0.022  1.0
  Mg  Mg36  1  0.837  0.163  0.022  1.0
  Mg  Mg37  1  0.837  0.675  0.478  1.0
[/CIF]
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The compound described by La2Mg17 crystallizes in the hexagonal P6_3/mmc space group. There are four inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 12-coordinate geometry to one Mg(2), two equivalent Mg(1), two equivalent Mg(3), four equivalent Mg(4), one La(1), and two equivalent La(2) atoms. In the second Mg site, Mg(2) is bonded in a 14-coordinate geometry to one Mg(2), three equivalent Mg(1), three equivalent Mg(3), six equivalent Mg(4), and one La(1) atom. In the third Mg site, Mg(3) is bonded to two equivalent Mg(2), four equivalent Mg(1), four equivalent Mg(4), and two equivalent La(1) atoms to form a mixture of distorted edge, face, and corner-sharing MgLa2Mg10 cuboctahedra. In the fourth Mg site, Mg(4) is bonded to two equivalent Mg(2), two equivalent Mg(3), two equivalent Mg(4), four equivalent Mg(1), one La(1), and one La(2) atom to form a mixture of distorted edge, face, and corner-sharing MgLa2Mg10 cuboctahedra. There are two inequivalent La sites. In the first La site, La(1) is bonded in a 20-coordinate geometry to two equivalent Mg(2), six equivalent Mg(1), six equivalent Mg(3), and six equivalent Mg(4) atoms. In the second La site, La(2) is bonded in a 18-coordinate geometry to six equivalent Mg(4) and twelve equivalent Mg(1) atoms. is represented by the CIF file [CIF]
data_La2Mg17
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   10.312
_cell_length_b   10.312
_cell_length_c   10.153
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   934.911
_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
  La  La0  1  0.667  0.333  0.250  1.0
  La  La1  1  0.333  0.667  0.750  1.0
  La  La2  1  0.000  0.000  0.750  1.0
  La  La3  1  0.000  0.000  0.250  1.0
  Mg  Mg4  1  0.163  0.837  0.522  1.0
  Mg  Mg5  1  0.163  0.325  0.522  1.0
  Mg  Mg6  1  0.675  0.837  0.522  1.0
  Mg  Mg7  1  0.325  0.163  0.022  1.0
  Mg  Mg8  1  0.333  0.667  0.102  1.0
  Mg  Mg9  1  0.667  0.333  0.602  1.0
  Mg  Mg10  1  0.667  0.333  0.898  1.0
  Mg  Mg11  1  0.333  0.667  0.398  1.0
  Mg  Mg12  1  0.500  0.000  0.000  1.0
  Mg  Mg13  1  0.500  0.500  0.500  1.0
  Mg  Mg14  1  0.000  0.500  0.500  1.0
  Mg  Mg15  1  0.000  0.500  0.000  1.0
  Mg  Mg16  1  0.500  0.500  0.000  1.0
  Mg  Mg17  1  0.500  0.000  0.500  1.0
  Mg  Mg18  1  0.328  0.964  0.250  1.0
  Mg  Mg19  1  0.364  0.328  0.750  1.0
  Mg  Mg20  1  0.964  0.636  0.750  1.0
  Mg  Mg21  1  0.036  0.364  0.250  1.0
  Mg  Mg22  1  0.636  0.672  0.250  1.0
  Mg  Mg23  1  0.364  0.036  0.750  1.0
  Mg  Mg24  1  0.672  0.636  0.750  1.0
  Mg  Mg25  1  0.672  0.036  0.750  1.0
  Mg  Mg26  1  0.964  0.328  0.750  1.0
  Mg  Mg27  1  0.036  0.672  0.250  1.0
  Mg  Mg28  1  0.636  0.964  0.250  1.0
  Mg  Mg29  1  0.328  0.364  0.250  1.0
  Mg  Mg30  1  0.163  0.325  0.978  1.0
  Mg  Mg31  1  0.837  0.163  0.478  1.0
  Mg  Mg32  1  0.325  0.163  0.478  1.0
  Mg  Mg33  1  0.675  0.837  0.978  1.0
  Mg  Mg34  1  0.163  0.837  0.978  1.0
  Mg  Mg35  1  0.837  0.675  0.022  1.0
  Mg  Mg36  1  0.837  0.163  0.022  1.0
  Mg  Mg37  1  0.837  0.675  0.478  1.0
[/CIF]
.