data_Sr6Mg23
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   10.54
_cell_length_b   10.54
_cell_length_c   10.54
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Sr6Mg23
_chemical_formula_sum   'Sr6 Mg23'
_cell_volume   827.52
_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
  Sr  Sr23  1  0.35  0.45  0.45  1.0
  Sr  Sr24  1  0.55  0.45  0.45  1.0
  Sr  Sr25  1  0.45  0.55  0.45  1.0
  Sr  Sr26  1  0.45  0.35  0.45  1.0
  Sr  Sr27  1  0.45  0.45  0.35  1.0
  Sr  Sr28  1  0.45  0.45  0.55  1.0
  Mg  Mg0  1  0.0  0.0  0.0  1.0
  Mg  Mg1  1  0.0  0.73  0.73  1.0
  Mg  Mg2  1  0.45  0.73  0.73  1.0
  Mg  Mg3  1  0.73  0.45  0.73  1.0
  Mg  Mg4  1  0.73  0.0  0.73  1.0
  Mg  Mg5  1  0.73  0.73  0.0  1.0
  Mg  Mg6  1  0.73  0.73  0.45  1.0
  Mg  Mg7  1  0.26  0.09  0.26  1.0
  Mg  Mg8  1  0.09  0.26  0.26  1.0
  Mg  Mg9  1  0.09  0.09  0.09  1.0
  Mg  Mg10  1  0.26  0.26  0.09  1.0
  Mg  Mg11  1  0.81  0.64  0.64  1.0
  Mg  Mg12  1  0.64  0.81  0.64  1.0
  Mg  Mg13  1  0.81  0.81  0.81  1.0
  Mg  Mg14  1  0.64  0.64  0.81  1.0
  Mg  Mg15  1  0.3  0.06  0.3  1.0
  Mg  Mg16  1  0.06  0.3  0.3  1.0
  Mg  Mg17  1  0.06  0.06  0.06  1.0
  Mg  Mg18  1  0.3  0.3  0.06  1.0
  Mg  Mg19  1  0.85  0.61  0.61  1.0
  Mg  Mg20  1  0.61  0.85  0.61  1.0
  Mg  Mg21  1  0.85  0.85  0.85  1.0
  Mg  Mg22  1  0.61  0.61  0.85  1.0

data_Sr6Mg23
_symmetry_space_group_name_H-M   R3m
_cell_length_a   10.54
_cell_length_b   10.54
_cell_length_c   25.81
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   Sr6Mg23
_chemical_formula_sum   'Sr18 Mg69'
_cell_volume   2482.56
_cell_formula_units_Z   3
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  '-y, x-y, z'
  3  '-x+y, -x, z'
  4  '-y, -x, z'
  5  '-x+y, y, z'
  6  'x, x-y, z'
  7  'x+1/3, y+2/3, z+2/3'
  8  '-y+1/3, x-y+2/3, z+2/3'
  9  '-x+y+1/3, -x+2/3, z+2/3'
  10  '-y+1/3, -x+2/3, z+2/3'
  11  '-x+y+1/3, y+2/3, z+2/3'
  12  'x+1/3, x-y+2/3, z+2/3'
  13  'x+2/3, y+1/3, z+1/3'
  14  '-y+2/3, x-y+1/3, z+1/3'
  15  '-x+y+2/3, -x+1/3, z+1/3'
  16  '-y+2/3, -x+1/3, z+1/3'
  17  '-x+y+2/3, y+1/3, z+1/3'
  18  'x+2/3, x-y+1/3, z+1/3'
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
  Sr  Sr0  9  0.03  0.07  0.51  1.0
  Sr  Sr1  9  0.07  0.03  0.58  1.0
  Mg  Mg2  9  0.06  0.12  0.3  1.0
  Mg  Mg3  9  0.08  0.16  0.31  1.0
  Mg  Mg4  9  0.09  0.18  0.18  1.0
  Mg  Mg5  9  0.12  0.06  0.79  1.0
  Mg  Mg6  9  0.16  0.08  0.78  1.0
  Mg  Mg7  9  0.18  0.09  0.37  1.0
  Mg  Mg8  3  0.0  0.0  0.0  1.0
  Mg  Mg9  3  0.0  0.0  0.15  1.0
  Mg  Mg10  3  0.0  0.0  0.19  1.0
  Mg  Mg11  3  0.0  0.0  0.91  1.0
  Mg  Mg12  3  0.0  0.0  0.94  1.0

Sr Sr Sr Sr Sr Sr Mg Mg Mg Mg Mg Mg Mg Mg Mg Mg Mg Mg Mg Mg Mg Mg Mg Mg Mg Mg Mg Mg Mg
Sr Sr Sr Sr Sr Sr Mg Mg Mg Mg Mg Mg Mg Mg Mg Mg Mg Mg Mg Mg Mg Mg Mg Mg Mg Mg Mg Mg Mg 0 3 o o o 0 4 o o o 1 5 o o o 1 2 o o o 2 5 o o o 3 4 o o o 6 23 o o o 7 27 - o o 7 19 - o o 8 28 o o o 8 20 o o o 8 26 o o o 8 18 o o o 9 28 o o o 9 20 o o o 9 25 o o o 9 17 o o o 10 27 o - o 10 19 o - o 11 27 o o - 11 19 o o - 12 26 o o o 12 18 o o o 12 25 o o o 12 17 o o o 13 21 o o o 14 22 o o o 15 23 o o o 16 24 o o o 17 25 o o o 18 26 o o o 19 27 o o o 20 28 o o o 
Mg23Sr6 crystallizes in the trigonal R3m space group. The structure is zero-dimensional and consists of nine magnesiomagnesium molecules, nine Mg clusters, and six Sr clusters. In three of the Mg clusters, there are three inequivalent Mg sites. In the first Mg site, Mg(5) is bonded in a single-bond geometry to one Mg(9) atom. The Mg(5)-Mg(9) bond length is 0.86 Å. In the second Mg site, Mg(1) is bonded in a single-bond geometry to one Mg(9) atom. The Mg(1)-Mg(9) bond length is 1.50 Å. In the third Mg site, Mg(9) is bonded in a linear geometry to one Mg(1) and one Mg(5) atom. In three of the Mg clusters, there are three inequivalent Mg sites. In the first Mg site, Mg(2) is bonded in a distorted single-bond geometry to one Mg(7) atom. The Mg(2)-Mg(7) bond length is 1.67 Å. In the second Mg site, Mg(7) is bonded in a single-bond geometry to one Mg(11) and three equivalent Mg(2) atoms. The Mg(7)-Mg(11) bond length is 0.86 Å. In the third Mg site, Mg(11) is bonded in a single-bond geometry to one Mg(7) atom. In three of the Mg clusters, there are three inequivalent Mg sites. In the first Mg site, Mg(10) is bonded in a single-bond geometry to one Mg(6) and two equivalent Mg(3) atoms. The Mg(10)-Mg(6) bond length is 0.49 Å. Both Mg(10)-Mg(3) bond lengths are 2.06 Å. In the second Mg site, Mg(3) is bonded in a 2-coordinate geometry to two equivalent Mg(10) atoms. In the third Mg site, Mg(6) is bonded in a distorted single-bond geometry to one Mg(10) atom. In each Sr cluster, Sr(1,2) is bonded in a 2-coordinate geometry to two equivalent Sr(1,2) atoms. Both Sr(1,2)-Sr(1,2) bond lengths are 1.07 Å.