The material described by Er15Fe8C25 crystallizes in the trigonal P3 space group. There are five inequivalent Er sites. In the first Er site, Er(1) is bonded in a 5-coordinate geometry to one C(5), one C(6), one C(7), one C(8), and one C(9) atom. In the second Er site, Er(2) is bonded in a 5-coordinate geometry to one C(7), two equivalent C(1), two equivalent C(4), and two equivalent C(8) atoms. In the third Er site, Er(3) is bonded in a 5-coordinate geometry to one C(8), two equivalent C(2), two equivalent C(3), and two equivalent C(7) atoms. In the fourth Er site, Er(4) is bonded in a 8-coordinate geometry to one C(1), one C(5), one C(6), one C(7), two equivalent C(2), and two equivalent C(3) atoms. In the fifth Er site, Er(5) is bonded to one C(2), one C(5), one C(6), one C(8), two equivalent C(1), and two equivalent C(4) atoms to form distorted ErC8 hexagonal bipyramids that share corners with four equivalent Er(5)C8 hexagonal bipyramids,  a cornercorner with one C(1)Er5C octahedra, and  a cornercorner with one C(2)Er5C octahedra. The corner-sharing octahedral tilt angles range from 107-113°. There are four inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in a distorted T-shaped geometry to one C(5), one C(6), and one C(9) atom. In the second Fe site, Fe(2) is bonded in a trigonal planar geometry to three equivalent C(3) atoms. In the third Fe site, Fe(3) is bonded in a trigonal planar geometry to three equivalent C(4) atoms. In the fourth Fe site, Fe(4) is bonded in a 4-coordinate geometry to one C(5), one C(6), one C(7), and one C(8) atom. There are nine inequivalent C sites. In the first C site, C(4) is bonded in a 6-coordinate geometry to two equivalent Er(2), two equivalent Er(5), one Fe(3), and one C(8) atom. In the second C site, C(5) is bonded in a 4-coordinate geometry to one Er(1), one Er(4), one Er(5), one Fe(1), one Fe(4), and one C(1) atom. In the third C site, C(6) is bonded in a 4-coordinate geometry to one Er(1), one Er(4), one Er(5), one Fe(1), one Fe(4), and one C(2) atom. In the fourth C site, C(7) is bonded in a 7-coordinate geometry to one Er(1), one Er(2), one Er(4), two equivalent Er(3), one Fe(4), and one C(3) atom. In the fifth C site, C(8) is bonded in a 7-coordinate geometry to one Er(1), one Er(3), one Er(5), two equivalent Er(2), one Fe(4), and one C(4) atom. In the sixth C site, C(9) is bonded in an octahedral geometry to three equivalent Er(1) and three equivalent Fe(1) atoms. In the seventh C site, C(1) is bonded to one Er(4), two equivalent Er(2), two equivalent Er(5), and one C(5) atom to form CEr5C octahedra that share  a cornercorner with one Er(5)C8 hexagonal bipyramid, corners with four equivalent C(1)Er5C octahedra, and edges with two equivalent C(2)Er5C octahedra. The corner-sharing octahedral tilt angles range from 7-33°. In the eighth C site, C(2) is bonded to one Er(5), two equivalent Er(3), two equivalent Er(4), and one C(6) atom to form CEr5C octahedra that share  a cornercorner with one Er(5)C8 hexagonal bipyramid, corners with four equivalent C(2)Er5C octahedra, and edges with two equivalent C(1)Er5C octahedra. The corner-sharing octahedral tilt angles range from 7-33°. In the ninth C site, C(3) is bonded in a 6-coordinate geometry to two equivalent Er(3), two equivalent Er(4), one Fe(2), and one C(7) atom. is represented by the CIF file [CIF]
data_Er15Fe8C25
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.068
_cell_length_b   11.802
_cell_length_c   11.801
_cell_angle_alpha   119.998
_cell_angle_beta   89.999
_cell_angle_gamma   89.994
_symmetry_Int_Tables_number   1
_cell_volume   611.313
_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
  Er  Er0  1  0.499  0.832  0.831  1.0
  Er  Er1  1  0.499  0.169  0.001  1.0
  Er  Er2  1  0.499  0.999  0.168  1.0
  Er  Er3  1  0.245  0.633  0.489  1.0
  Er  Er4  1  0.245  0.511  0.145  1.0
  Er  Er5  1  0.245  0.855  0.367  1.0
  Er  Er6  1  0.755  0.367  0.855  1.0
  Er  Er7  1  0.755  0.145  0.512  1.0
  Er  Er8  1  0.755  0.488  0.633  1.0
  Er  Er9  1  0.252  0.116  0.711  1.0
  Er  Er10  1  0.252  0.288  0.405  1.0
  Er  Er11  1  0.252  0.595  0.884  1.0
  Er  Er12  1  0.747  0.884  0.596  1.0
  Er  Er13  1  0.747  0.404  0.288  1.0
  Er  Er14  1  0.747  0.712  0.116  1.0
  Fe  Fe15  1  0.008  0.133  0.132  1.0
  Fe  Fe16  1  0.008  0.868  0.001  1.0
  Fe  Fe17  1  0.008  0.999  0.867  1.0
  Fe  Fe18  1  0.265  0.333  0.667  1.0
  Fe  Fe19  1  0.736  0.667  0.333  1.0
  Fe  Fe20  1  0.001  0.751  0.750  1.0
  Fe  Fe21  1  0.001  0.250  0.001  1.0
  Fe  Fe22  1  0.001  0.999  0.249  1.0
  C  C23  1  0.239  0.877  0.581  1.0
  C  C24  1  0.239  0.419  0.296  1.0
  C  C25  1  0.239  0.703  0.123  1.0
  C  C26  1  0.760  0.124  0.704  1.0
  C  C27  1  0.760  0.296  0.419  1.0
  C  C28  1  0.760  0.581  0.876  1.0
  C  C29  1  0.258  0.358  0.833  1.0
  C  C30  1  0.258  0.167  0.525  1.0
  C  C31  1  0.258  0.475  0.642  1.0
  C  C32  1  0.743  0.641  0.474  1.0
  C  C33  1  0.743  0.526  0.167  1.0
  C  C34  1  0.743  0.833  0.359  1.0
  C  C35  1  0.184  0.888  0.701  1.0
  C  C36  1  0.184  0.299  0.187  1.0
  C  C37  1  0.184  0.813  0.112  1.0
  C  C38  1  0.811  0.109  0.813  1.0
  C  C39  1  0.811  0.187  0.297  1.0
  C  C40  1  0.811  0.703  0.891  1.0
  C  C41  1  0.238  0.318  0.923  1.0
  C  C42  1  0.238  0.077  0.396  1.0
  C  C43  1  0.239  0.604  0.682  1.0
  C  C44  1  0.762  0.682  0.604  1.0
  C  C45  1  0.762  0.396  0.078  1.0
  C  C46  1  0.762  0.922  0.318  1.0
  C  C47  1  0.229  0.000  0.000  1.0
[/CIF]
.
The material described by Er15Fe8C25 crystallizes in the trigonal P3 space group. There are five inequivalent Er sites. In the first Er site, Er(1) is bonded in a 5-coordinate geometry to one C(5), one C(6), one C(7), one C(8), and one C(9) atom. In the second Er site, Er(2) is bonded in a 5-coordinate geometry to one C(7), two equivalent C(1), two equivalent C(4), and two equivalent C(8) atoms. In the third Er site, Er(3) is bonded in a 5-coordinate geometry to one C(8), two equivalent C(2), two equivalent C(3), and two equivalent C(7) atoms. In the fourth Er site, Er(4) is bonded in a 8-coordinate geometry to one C(1), one C(5), one C(6), one C(7), two equivalent C(2), and two equivalent C(3) atoms. In the fifth Er site, Er(5) is bonded to one C(2), one C(5), one C(6), one C(8), two equivalent C(1), and two equivalent C(4) atoms to form distorted ErC8 hexagonal bipyramids that share corners with four equivalent Er(5)C8 hexagonal bipyramids,  a cornercorner with one C(1)Er5C octahedra, and  a cornercorner with one C(2)Er5C octahedra. The corner-sharing octahedral tilt angles range from 107-113°. There are four inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in a distorted T-shaped geometry to one C(5), one C(6), and one C(9) atom. In the second Fe site, Fe(2) is bonded in a trigonal planar geometry to three equivalent C(3) atoms. In the third Fe site, Fe(3) is bonded in a trigonal planar geometry to three equivalent C(4) atoms. In the fourth Fe site, Fe(4) is bonded in a 4-coordinate geometry to one C(5), one C(6), one C(7), and one C(8) atom. There are nine inequivalent C sites. In the first C site, C(4) is bonded in a 6-coordinate geometry to two equivalent Er(2), two equivalent Er(5), one Fe(3), and one C(8) atom. In the second C site, C(5) is bonded in a 4-coordinate geometry to one Er(1), one Er(4), one Er(5), one Fe(1), one Fe(4), and one C(1) atom. In the third C site, C(6) is bonded in a 4-coordinate geometry to one Er(1), one Er(4), one Er(5), one Fe(1), one Fe(4), and one C(2) atom. In the fourth C site, C(7) is bonded in a 7-coordinate geometry to one Er(1), one Er(2), one Er(4), two equivalent Er(3), one Fe(4), and one C(3) atom. In the fifth C site, C(8) is bonded in a 7-coordinate geometry to one Er(1), one Er(3), one Er(5), two equivalent Er(2), one Fe(4), and one C(4) atom. In the sixth C site, C(9) is bonded in an octahedral geometry to three equivalent Er(1) and three equivalent Fe(1) atoms. In the seventh C site, C(1) is bonded to one Er(4), two equivalent Er(2), two equivalent Er(5), and one C(5) atom to form CEr5C octahedra that share  a cornercorner with one Er(5)C8 hexagonal bipyramid, corners with four equivalent C(1)Er5C octahedra, and edges with two equivalent C(2)Er5C octahedra. The corner-sharing octahedral tilt angles range from 7-33°. In the eighth C site, C(2) is bonded to one Er(5), two equivalent Er(3), two equivalent Er(4), and one C(6) atom to form CEr5C octahedra that share  a cornercorner with one Er(5)C8 hexagonal bipyramid, corners with four equivalent C(2)Er5C octahedra, and edges with two equivalent C(1)Er5C octahedra. The corner-sharing octahedral tilt angles range from 7-33°. In the ninth C site, C(3) is bonded in a 6-coordinate geometry to two equivalent Er(3), two equivalent Er(4), one Fe(2), and one C(7) atom. is represented by the CIF file [CIF]
data_Er15Fe8C25
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.068
_cell_length_b   11.802
_cell_length_c   11.801
_cell_angle_alpha   119.998
_cell_angle_beta   89.999
_cell_angle_gamma   89.994
_symmetry_Int_Tables_number   1
_cell_volume   611.313
_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
  Er  Er0  1  0.499  0.832  0.831  1.0
  Er  Er1  1  0.499  0.169  0.001  1.0
  Er  Er2  1  0.499  0.999  0.168  1.0
  Er  Er3  1  0.245  0.633  0.489  1.0
  Er  Er4  1  0.245  0.511  0.145  1.0
  Er  Er5  1  0.245  0.855  0.367  1.0
  Er  Er6  1  0.755  0.367  0.855  1.0
  Er  Er7  1  0.755  0.145  0.512  1.0
  Er  Er8  1  0.755  0.488  0.633  1.0
  Er  Er9  1  0.252  0.116  0.711  1.0
  Er  Er10  1  0.252  0.288  0.405  1.0
  Er  Er11  1  0.252  0.595  0.884  1.0
  Er  Er12  1  0.747  0.884  0.596  1.0
  Er  Er13  1  0.747  0.404  0.288  1.0
  Er  Er14  1  0.747  0.712  0.116  1.0
  Fe  Fe15  1  0.008  0.133  0.132  1.0
  Fe  Fe16  1  0.008  0.868  0.001  1.0
  Fe  Fe17  1  0.008  0.999  0.867  1.0
  Fe  Fe18  1  0.265  0.333  0.667  1.0
  Fe  Fe19  1  0.736  0.667  0.333  1.0
  Fe  Fe20  1  0.001  0.751  0.750  1.0
  Fe  Fe21  1  0.001  0.250  0.001  1.0
  Fe  Fe22  1  0.001  0.999  0.249  1.0
  C  C23  1  0.239  0.877  0.581  1.0
  C  C24  1  0.239  0.419  0.296  1.0
  C  C25  1  0.239  0.703  0.123  1.0
  C  C26  1  0.760  0.124  0.704  1.0
  C  C27  1  0.760  0.296  0.419  1.0
  C  C28  1  0.760  0.581  0.876  1.0
  C  C29  1  0.258  0.358  0.833  1.0
  C  C30  1  0.258  0.167  0.525  1.0
  C  C31  1  0.258  0.475  0.642  1.0
  C  C32  1  0.743  0.641  0.474  1.0
  C  C33  1  0.743  0.526  0.167  1.0
  C  C34  1  0.743  0.833  0.359  1.0
  C  C35  1  0.184  0.888  0.701  1.0
  C  C36  1  0.184  0.299  0.187  1.0
  C  C37  1  0.184  0.813  0.112  1.0
  C  C38  1  0.811  0.109  0.813  1.0
  C  C39  1  0.811  0.187  0.297  1.0
  C  C40  1  0.811  0.703  0.891  1.0
  C  C41  1  0.238  0.318  0.923  1.0
  C  C42  1  0.238  0.077  0.396  1.0
  C  C43  1  0.239  0.604  0.682  1.0
  C  C44  1  0.762  0.682  0.604  1.0
  C  C45  1  0.762  0.396  0.078  1.0
  C  C46  1  0.762  0.922  0.318  1.0
  C  C47  1  0.229  0.000  0.000  1.0
[/CIF]
.