The material structure described by Er3(Co2Sn)4 is Hexagonal Laves-derived structured and crystallizes in the hexagonal P6_3mc space group. Er(1) is bonded in a 12-coordinate geometry to two equivalent Co(1), two equivalent Co(2), two equivalent Co(3), two equivalent Sn(1), and four equivalent Sn(2) atoms. There are four inequivalent Co sites. In the first Co site, Co(1) is bonded in a 10-coordinate geometry to six equivalent Er(1), one Sn(1), and three equivalent Sn(2) atoms. In the second Co site, Co(2) is bonded to two equivalent Er(1), two equivalent Co(2), two equivalent Co(4), three equivalent Co(3), and three equivalent Sn(2) atoms to form distorted CoEr2Co7Sn3 cuboctahedra that share corners with four equivalent Co(2)Er2Co7Sn3 cuboctahedra, corners with five equivalent Sn(2)Er4Co8 cuboctahedra, faces with two equivalent Co(4)Co9Sn3 cuboctahedra, faces with six equivalent Co(2)Er2Co7Sn3 cuboctahedra, and faces with six equivalent Sn(2)Er4Co8 cuboctahedra. In the third Co site, Co(3) is bonded in a 10-coordinate geometry to two equivalent Er(1), one Co(4), three equivalent Co(2), one Sn(1), and three equivalent Sn(2) atoms. In the fourth Co site, Co(4) is bonded to three equivalent Co(3), six equivalent Co(2), and three equivalent Sn(2) atoms to form CoCo9Sn3 cuboctahedra that share corners with three equivalent Sn(2)Er4Co8 cuboctahedra, faces with two equivalent Co(4)Co9Sn3 cuboctahedra, faces with six equivalent Co(2)Er2Co7Sn3 cuboctahedra, and faces with six equivalent Sn(2)Er4Co8 cuboctahedra. There are two inequivalent Sn sites. In the first Sn site, Sn(1) is bonded in a 10-coordinate geometry to six equivalent Er(1), one Co(1), and three equivalent Co(3) atoms. In the second Sn site, Sn(2) is bonded to four equivalent Er(1), one Co(1), one Co(4), three equivalent Co(2), and three equivalent Co(3) atoms to form distorted SnEr4Co8 cuboctahedra that share  a cornercorner with one Co(4)Co9Sn3 cuboctahedra, corners with four equivalent Sn(2)Er4Co8 cuboctahedra, corners with five equivalent Co(2)Er2Co7Sn3 cuboctahedra, faces with two equivalent Co(4)Co9Sn3 cuboctahedra, faces with six equivalent Co(2)Er2Co7Sn3 cuboctahedra, and faces with eight equivalent Sn(2)Er4Co8 cuboctahedra. is represented by the CIF card [CIF]
data_Er3(Co2Sn)4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.508
_cell_length_b   8.779
_cell_length_c   8.779
_cell_angle_alpha   120.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   501.156
_cell_formula_units_Z   2
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  0.785  0.475  0.951  1.0
  Er  Er1  1  0.785  0.475  0.525  1.0
  Er  Er2  1  0.285  0.525  0.049  1.0
  Er  Er3  1  0.785  0.049  0.525  1.0
  Er  Er4  1  0.285  0.525  0.475  1.0
  Er  Er5  1  0.285  0.951  0.475  1.0
  Co  Co6  1  0.629  0.667  0.333  1.0
  Co  Co7  1  0.129  0.333  0.667  1.0
  Co  Co8  1  0.755  0.099  0.199  1.0
  Co  Co9  1  0.755  0.099  0.901  1.0
  Co  Co10  1  0.255  0.901  0.801  1.0
  Co  Co11  1  0.755  0.801  0.901  1.0
  Co  Co12  1  0.255  0.901  0.099  1.0
  Co  Co13  1  0.255  0.199  0.099  1.0
  Co  Co14  1  0.941  0.839  0.678  1.0
  Co  Co15  1  0.941  0.839  0.161  1.0
  Co  Co16  1  0.441  0.161  0.322  1.0
  Co  Co17  1  0.941  0.322  0.161  1.0
  Co  Co18  1  0.441  0.161  0.839  1.0
  Co  Co19  1  0.441  0.678  0.839  1.0
  Co  Co20  1  0.997  0.000  0.000  1.0
  Co  Co21  1  0.497  0.000  0.000  1.0
  Sn  Sn22  1  0.979  0.667  0.333  1.0
  Sn  Sn23  1  0.479  0.333  0.667  1.0
  Sn  Sn24  1  0.572  0.829  0.658  1.0
  Sn  Sn25  1  0.572  0.829  0.171  1.0
  Sn  Sn26  1  0.072  0.171  0.342  1.0
  Sn  Sn27  1  0.572  0.342  0.171  1.0
  Sn  Sn28  1  0.072  0.171  0.829  1.0
  Sn  Sn29  1  0.072  0.658  0.829  1.0
[/CIF]
.
The material structure described by Er3(Co2Sn)4 is Hexagonal Laves-derived structured and crystallizes in the hexagonal P6_3mc space group. Er(1) is bonded in a 12-coordinate geometry to two equivalent Co(1), two equivalent Co(2), two equivalent Co(3), two equivalent Sn(1), and four equivalent Sn(2) atoms. There are four inequivalent Co sites. In the first Co site, Co(1) is bonded in a 10-coordinate geometry to six equivalent Er(1), one Sn(1), and three equivalent Sn(2) atoms. In the second Co site, Co(2) is bonded to two equivalent Er(1), two equivalent Co(2), two equivalent Co(4), three equivalent Co(3), and three equivalent Sn(2) atoms to form distorted CoEr2Co7Sn3 cuboctahedra that share corners with four equivalent Co(2)Er2Co7Sn3 cuboctahedra, corners with five equivalent Sn(2)Er4Co8 cuboctahedra, faces with two equivalent Co(4)Co9Sn3 cuboctahedra, faces with six equivalent Co(2)Er2Co7Sn3 cuboctahedra, and faces with six equivalent Sn(2)Er4Co8 cuboctahedra. In the third Co site, Co(3) is bonded in a 10-coordinate geometry to two equivalent Er(1), one Co(4), three equivalent Co(2), one Sn(1), and three equivalent Sn(2) atoms. In the fourth Co site, Co(4) is bonded to three equivalent Co(3), six equivalent Co(2), and three equivalent Sn(2) atoms to form CoCo9Sn3 cuboctahedra that share corners with three equivalent Sn(2)Er4Co8 cuboctahedra, faces with two equivalent Co(4)Co9Sn3 cuboctahedra, faces with six equivalent Co(2)Er2Co7Sn3 cuboctahedra, and faces with six equivalent Sn(2)Er4Co8 cuboctahedra. There are two inequivalent Sn sites. In the first Sn site, Sn(1) is bonded in a 10-coordinate geometry to six equivalent Er(1), one Co(1), and three equivalent Co(3) atoms. In the second Sn site, Sn(2) is bonded to four equivalent Er(1), one Co(1), one Co(4), three equivalent Co(2), and three equivalent Co(3) atoms to form distorted SnEr4Co8 cuboctahedra that share  a cornercorner with one Co(4)Co9Sn3 cuboctahedra, corners with four equivalent Sn(2)Er4Co8 cuboctahedra, corners with five equivalent Co(2)Er2Co7Sn3 cuboctahedra, faces with two equivalent Co(4)Co9Sn3 cuboctahedra, faces with six equivalent Co(2)Er2Co7Sn3 cuboctahedra, and faces with eight equivalent Sn(2)Er4Co8 cuboctahedra. is represented by the CIF card [CIF]
data_Er3(Co2Sn)4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.508
_cell_length_b   8.779
_cell_length_c   8.779
_cell_angle_alpha   120.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   501.156
_cell_formula_units_Z   2
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  0.785  0.475  0.951  1.0
  Er  Er1  1  0.785  0.475  0.525  1.0
  Er  Er2  1  0.285  0.525  0.049  1.0
  Er  Er3  1  0.785  0.049  0.525  1.0
  Er  Er4  1  0.285  0.525  0.475  1.0
  Er  Er5  1  0.285  0.951  0.475  1.0
  Co  Co6  1  0.629  0.667  0.333  1.0
  Co  Co7  1  0.129  0.333  0.667  1.0
  Co  Co8  1  0.755  0.099  0.199  1.0
  Co  Co9  1  0.755  0.099  0.901  1.0
  Co  Co10  1  0.255  0.901  0.801  1.0
  Co  Co11  1  0.755  0.801  0.901  1.0
  Co  Co12  1  0.255  0.901  0.099  1.0
  Co  Co13  1  0.255  0.199  0.099  1.0
  Co  Co14  1  0.941  0.839  0.678  1.0
  Co  Co15  1  0.941  0.839  0.161  1.0
  Co  Co16  1  0.441  0.161  0.322  1.0
  Co  Co17  1  0.941  0.322  0.161  1.0
  Co  Co18  1  0.441  0.161  0.839  1.0
  Co  Co19  1  0.441  0.678  0.839  1.0
  Co  Co20  1  0.997  0.000  0.000  1.0
  Co  Co21  1  0.497  0.000  0.000  1.0
  Sn  Sn22  1  0.979  0.667  0.333  1.0
  Sn  Sn23  1  0.479  0.333  0.667  1.0
  Sn  Sn24  1  0.572  0.829  0.658  1.0
  Sn  Sn25  1  0.572  0.829  0.171  1.0
  Sn  Sn26  1  0.072  0.171  0.342  1.0
  Sn  Sn27  1  0.572  0.342  0.171  1.0
  Sn  Sn28  1  0.072  0.171  0.829  1.0
  Sn  Sn29  1  0.072  0.658  0.829  1.0
[/CIF]
.