The crystal structure described by La3Ni2Sn7 crystallizes in the orthorhombic Cmmm space group. There are two inequivalent La sites. In the first La site, La(1) is bonded in a 14-coordinate geometry to four equivalent Ni(1), two equivalent Sn(1), two equivalent Sn(4), and six equivalent Sn(2) atoms. In the second La site, La(2) is bonded to two equivalent Ni(1), four equivalent Sn(1), four equivalent Sn(3), and four equivalent Sn(4) atoms to form a mixture of distorted corner and face-sharing LaNi2Sn12 cuboctahedra. Ni(1) is bonded in a 5-coordinate geometry to one La(2), four equivalent La(1), one Sn(2), two equivalent Sn(1), and two equivalent Sn(4) atoms. There are four inequivalent Sn sites. In the first Sn site, Sn(1) is bonded in a 6-coordinate geometry to two equivalent La(1), two equivalent La(2), and two equivalent Ni(1) atoms. In the second Sn site, Sn(2) is bonded in a 9-coordinate geometry to six equivalent La(1), one Ni(1), and two equivalent Sn(2) atoms. In the third Sn site, Sn(3) is bonded in a square co-planar geometry to four equivalent La(2) atoms. In the fourth Sn site, Sn(4) is bonded in a 6-coordinate geometry to two equivalent La(1), two equivalent La(2), and two equivalent Ni(1) atoms. is represented by the CIF file [CIF]
data_La3Ni2Sn7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.623
_cell_length_b   4.633
_cell_length_c   14.076
_cell_angle_alpha   90.000
_cell_angle_beta   99.451
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   297.402
_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
  La  La0  1  0.184  0.000  0.369  1.0
  La  La1  1  0.816  0.000  0.631  1.0
  La  La2  1  0.500  0.500  0.000  1.0
  Ni  Ni3  1  0.372  0.500  0.744  1.0
  Ni  Ni4  1  0.628  0.500  0.256  1.0
  Sn  Sn5  1  0.090  0.500  0.180  1.0
  Sn  Sn6  1  0.910  0.500  0.820  1.0
  Sn  Sn7  1  0.282  0.500  0.563  1.0
  Sn  Sn8  1  0.718  0.500  0.437  1.0
  Sn  Sn9  1  0.000  0.000  0.000  1.0
  Sn  Sn10  1  0.590  0.000  0.180  1.0
  Sn  Sn11  1  0.410  0.000  0.820  1.0
[/CIF]
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The crystal structure described by La3Ni2Sn7 crystallizes in the orthorhombic Cmmm space group. There are two inequivalent La sites. In the first La site, La(1) is bonded in a 14-coordinate geometry to four equivalent Ni(1), two equivalent Sn(1), two equivalent Sn(4), and six equivalent Sn(2) atoms. In the second La site, La(2) is bonded to two equivalent Ni(1), four equivalent Sn(1), four equivalent Sn(3), and four equivalent Sn(4) atoms to form a mixture of distorted corner and face-sharing LaNi2Sn12 cuboctahedra. Ni(1) is bonded in a 5-coordinate geometry to one La(2), four equivalent La(1), one Sn(2), two equivalent Sn(1), and two equivalent Sn(4) atoms. There are four inequivalent Sn sites. In the first Sn site, Sn(1) is bonded in a 6-coordinate geometry to two equivalent La(1), two equivalent La(2), and two equivalent Ni(1) atoms. In the second Sn site, Sn(2) is bonded in a 9-coordinate geometry to six equivalent La(1), one Ni(1), and two equivalent Sn(2) atoms. In the third Sn site, Sn(3) is bonded in a square co-planar geometry to four equivalent La(2) atoms. In the fourth Sn site, Sn(4) is bonded in a 6-coordinate geometry to two equivalent La(1), two equivalent La(2), and two equivalent Ni(1) atoms. is represented by the CIF file [CIF]
data_La3Ni2Sn7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.623
_cell_length_b   4.633
_cell_length_c   14.076
_cell_angle_alpha   90.000
_cell_angle_beta   99.451
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   297.402
_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
  La  La0  1  0.184  0.000  0.369  1.0
  La  La1  1  0.816  0.000  0.631  1.0
  La  La2  1  0.500  0.500  0.000  1.0
  Ni  Ni3  1  0.372  0.500  0.744  1.0
  Ni  Ni4  1  0.628  0.500  0.256  1.0
  Sn  Sn5  1  0.090  0.500  0.180  1.0
  Sn  Sn6  1  0.910  0.500  0.820  1.0
  Sn  Sn7  1  0.282  0.500  0.563  1.0
  Sn  Sn8  1  0.718  0.500  0.437  1.0
  Sn  Sn9  1  0.000  0.000  0.000  1.0
  Sn  Sn10  1  0.590  0.000  0.180  1.0
  Sn  Sn11  1  0.410  0.000  0.820  1.0
[/CIF]
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