The structure described by BC7 crystallizes in the orthorhombic Pmm2 space group. B(1) is bonded to two equivalent C(1) and two equivalent C(2) atoms to form BC4 tetrahedra that share corners with two equivalent B(1)C4 tetrahedra, corners with two equivalent C(4)C4 tetrahedra, and corners with eight equivalent C(5)C4 tetrahedra. There are five inequivalent C sites. In the first C site, C(1) is bonded to one B(1), one C(4), and two equivalent C(5) atoms to form distorted CBC3 tetrahedra that share corners with four equivalent C(2)B2C2 tetrahedra, corners with four equivalent C(1)BC3 tetrahedra, and corners with four equivalent C(3)C4 tetrahedra. In the second C site, C(2) is bonded to two equivalent B(1) and two equivalent C(5) atoms to form distorted CB2C2 tetrahedra that share corners with two equivalent C(2)B2C2 tetrahedra, corners with two equivalent C(3)C4 tetrahedra, and corners with eight equivalent C(1)BC3 tetrahedra. In the third C site, C(3) is bonded to two equivalent C(4) and two equivalent C(5) atoms to form CC4 tetrahedra that share corners with two equivalent C(2)B2C2 tetrahedra, corners with two equivalent C(3)C4 tetrahedra, and corners with eight equivalent C(1)BC3 tetrahedra. In the fourth C site, C(4) is bonded to two equivalent C(1) and two equivalent C(3) atoms to form CC4 tetrahedra that share corners with two equivalent B(1)C4 tetrahedra, corners with two equivalent C(4)C4 tetrahedra, and corners with eight equivalent C(5)C4 tetrahedra. In the fifth C site, C(5) is bonded to one C(2), one C(3), and two equivalent C(1) atoms to form CC4 tetrahedra that share corners with four equivalent B(1)C4 tetrahedra, corners with four equivalent C(4)C4 tetrahedra, and corners with four equivalent C(5)C4 tetrahedra. is represented by the CIF file [CIF]
data_BC7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   2.513
_cell_length_b   3.690
_cell_length_c   5.122
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   47.498
_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
  B  B0  1  0.500  0.657  0.500  1.0
  C  C1  1  0.500  0.899  0.241  1.0
  C  C2  1  0.500  0.899  0.759  1.0
  C  C3  1  0.000  0.361  0.500  1.0
  C  C4  1  0.000  0.402  0.000  1.0
  C  C5  1  0.500  0.645  0.000  1.0
  C  C6  1  0.000  0.142  0.246  1.0
  C  C7  1  0.000  0.142  0.754  1.0
[/CIF]
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The structure described by BC7 crystallizes in the orthorhombic Pmm2 space group. B(1) is bonded to two equivalent C(1) and two equivalent C(2) atoms to form BC4 tetrahedra that share corners with two equivalent B(1)C4 tetrahedra, corners with two equivalent C(4)C4 tetrahedra, and corners with eight equivalent C(5)C4 tetrahedra. There are five inequivalent C sites. In the first C site, C(1) is bonded to one B(1), one C(4), and two equivalent C(5) atoms to form distorted CBC3 tetrahedra that share corners with four equivalent C(2)B2C2 tetrahedra, corners with four equivalent C(1)BC3 tetrahedra, and corners with four equivalent C(3)C4 tetrahedra. In the second C site, C(2) is bonded to two equivalent B(1) and two equivalent C(5) atoms to form distorted CB2C2 tetrahedra that share corners with two equivalent C(2)B2C2 tetrahedra, corners with two equivalent C(3)C4 tetrahedra, and corners with eight equivalent C(1)BC3 tetrahedra. In the third C site, C(3) is bonded to two equivalent C(4) and two equivalent C(5) atoms to form CC4 tetrahedra that share corners with two equivalent C(2)B2C2 tetrahedra, corners with two equivalent C(3)C4 tetrahedra, and corners with eight equivalent C(1)BC3 tetrahedra. In the fourth C site, C(4) is bonded to two equivalent C(1) and two equivalent C(3) atoms to form CC4 tetrahedra that share corners with two equivalent B(1)C4 tetrahedra, corners with two equivalent C(4)C4 tetrahedra, and corners with eight equivalent C(5)C4 tetrahedra. In the fifth C site, C(5) is bonded to one C(2), one C(3), and two equivalent C(1) atoms to form CC4 tetrahedra that share corners with four equivalent B(1)C4 tetrahedra, corners with four equivalent C(4)C4 tetrahedra, and corners with four equivalent C(5)C4 tetrahedra. is represented by the CIF file [CIF]
data_BC7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   2.513
_cell_length_b   3.690
_cell_length_c   5.122
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   47.498
_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
  B  B0  1  0.500  0.657  0.500  1.0
  C  C1  1  0.500  0.899  0.241  1.0
  C  C2  1  0.500  0.899  0.759  1.0
  C  C3  1  0.000  0.361  0.500  1.0
  C  C4  1  0.000  0.402  0.000  1.0
  C  C5  1  0.500  0.645  0.000  1.0
  C  C6  1  0.000  0.142  0.246  1.0
  C  C7  1  0.000  0.142  0.754  1.0
[/CIF]
.