data_Sr12C17
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.16
_cell_length_b   9.16
_cell_length_c   9.16
_cell_angle_alpha   109.47
_cell_angle_beta   109.47
_cell_angle_gamma   109.47
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Sr12C17
_chemical_formula_sum   'Sr12 C17'
_cell_volume   590.99
_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  Sr17  1  0.19  0.19  0.73  1.0
  Sr  Sr18  1  0.09  0.09  0.44  1.0
  Sr  Sr19  1  0.81  0.19  0.85  1.0
  Sr  Sr20  1  0.19  0.81  0.85  1.0
  Sr  Sr21  1  0.73  0.19  0.19  1.0
  Sr  Sr22  1  0.44  0.09  0.09  1.0
  Sr  Sr23  1  0.85  0.81  0.19  1.0
  Sr  Sr24  1  0.85  0.19  0.81  1.0
  Sr  Sr25  1  0.19  0.73  0.19  1.0
  Sr  Sr26  1  0.09  0.44  0.09  1.0
  Sr  Sr27  1  0.19  0.85  0.81  1.0
  Sr  Sr28  1  0.81  0.85  0.19  1.0
  C  C0  1  0.82  0.82  0.04  1.0
  C  C1  1  0.47  0.47  0.33  1.0
  C  C2  1  0.47  0.53  0.25  1.0
  C  C3  1  0.53  0.47  0.25  1.0
  C  C4  1  0.04  0.82  0.82  1.0
  C  C5  1  0.33  0.47  0.47  1.0
  C  C6  1  0.25  0.47  0.53  1.0
  C  C7  1  0.25  0.53  0.47  1.0
  C  C8  1  0.82  0.04  0.82  1.0
  C  C9  1  0.47  0.33  0.47  1.0
  C  C10  1  0.53  0.25  0.47  1.0
  C  C11  1  0.47  0.25  0.53  1.0
  C  C12  1  0.21  0.21  0.21  1.0
  C  C13  1  0.07  0.07  0.93  1.0
  C  C14  1  0.07  0.93  0.07  1.0
  C  C15  1  0.93  0.07  0.07  1.0
  C  C16  1  0.0  0.0  0.0  1.0

data_Sr12C17
_symmetry_space_group_name_H-M   R3m
_cell_length_a   14.95
_cell_length_b   14.95
_cell_length_c   9.16
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   Sr12C17
_chemical_formula_sum   'Sr36 C51'
_cell_volume   1772.98
_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+2/3, y+1/3, z+1/3'
  8  '-y+2/3, x-y+1/3, z+1/3'
  9  '-x+y+2/3, -x+1/3, z+1/3'
  10  '-y+2/3, -x+1/3, z+1/3'
  11  '-x+y+2/3, y+1/3, z+1/3'
  12  'x+2/3, x-y+1/3, z+1/3'
  13  'x+1/3, y+2/3, z+2/3'
  14  '-y+1/3, x-y+2/3, z+2/3'
  15  '-x+y+1/3, -x+2/3, z+2/3'
  16  '-y+1/3, -x+2/3, z+2/3'
  17  '-x+y+1/3, y+2/3, z+2/3'
  18  'x+1/3, x-y+2/3, z+2/3'
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  18  0.19  0.42  0.62  1.0
  Sr  Sr1  9  0.02  0.51  0.71  1.0
  Sr  Sr2  9  0.22  0.43  0.88  1.0
  C  C3  18  0.05  0.17  0.42  1.0
  C  C4  9  0.05  0.1  0.42  1.0
  C  C5  9  0.05  0.1  0.02  1.0
  C  C6  9  0.15  0.07  0.89  1.0
  C  C7  3  0.0  0.0  -0.0  1.0
  C  C8  3  0.0  0.0  0.21  1.0

Sr Sr Sr Sr Sr Sr Sr Sr Sr Sr Sr Sr C C C C C C C C C C C C C C C C C
Sr Sr Sr Sr Sr Sr Sr Sr Sr Sr Sr Sr C C C C C C C C C C C C C C C C C 0 1 o o o 1 11 - - o 1 6 - - o 2 7 o o o 2 9 + o + 2 20 o o o 3 10 o o o 3 5 o + + 3 16 o o o 4 5 o o o 5 10 o - - 6 11 o o o 6 12 o o o 7 9 + o + 7 20 o o o 8 9 o o o 10 16 o o o 11 12 o o o 13 14 o o o 13 15 o o o 13 24 o o o 14 15 o o o 17 19 o o o 17 18 o o o 17 24 o o o 18 19 o o o 21 23 o o o 21 22 o o o 21 24 o o o 22 23 o o o 24 28 o o o 24 25 o o - 24 27 - o o 24 26 o - o 25 28 o o + 26 28 o + o 27 28 + o o 
Sr12C17 crystallizes in the trigonal R3m space group. There are three inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a distorted single-bond geometry to one Sr(2) and one C(5) atom. The Sr(1)-Sr(2) bond length is 2.19 Å. The Sr(1)-C(5) bond length is 2.76 Å. In the second Sr site, Sr(2) is bonded in a 8-coordinate geometry to one Sr(1), two equivalent Sr(3), one C(4), two equivalent C(3), and two equivalent C(5) atoms. Both Sr(2)-Sr(3) bond lengths are 2.41 Å. The Sr(2)-C(4) bond length is 3.01 Å. Both Sr(2)-C(3) bond lengths are 2.95 Å. Both Sr(2)-C(5) bond lengths are 3.12 Å. In the third Sr site, Sr(3) is bonded in a distorted L-shaped geometry to one Sr(2), one Sr(3), and one C(1) atom. The Sr(3)-Sr(3) bond length is 0.59 Å. The Sr(3)-C(1) bond length is 1.40 Å. There are six inequivalent C sites. In the first C site, C(1) is bonded in a 2-coordinate geometry to two equivalent Sr(3) atoms. In the second C site, C(2) is bonded in a 2-coordinate geometry to two equivalent C(3) atoms. Both C(2)-C(3) bond lengths are 1.04 Å. In the third C site, C(3) is bonded in a 3-coordinate geometry to one Sr(2), one C(2), and one C(3) atom. The C(3)-C(3) bond length is 0.90 Å. In the fourth C site, C(4) is bonded in a 7-coordinate geometry to three equivalent Sr(2), one C(6), and three equivalent C(5) atoms. The C(4)-C(6) bond length is 1.95 Å. All C(4)-C(5) bond lengths are 2.14 Å. In the fifth C site, C(5) is bonded in a distorted linear geometry to one Sr(1), two equivalent Sr(2), one C(4), and one C(6) atom. The C(5)-C(6) bond length is 1.29 Å. In the sixth C site, C(6) is bonded in a distorted trigonal planar geometry to one C(4) and three equivalent C(5) atoms.