The material structure described by Er2Co12Ni5 crystallizes in the hexagonal P6_3/mmc space group. There are two inequivalent Er sites. In the first Er site, Er(1) is bonded in a 18-coordinate geometry to six equivalent Co(1) and twelve equivalent Co(2) atoms. In the second Er site, Er(2) is bonded in a 20-coordinate geometry to six equivalent Co(1), six equivalent Co(2), two equivalent Ni(1), and six equivalent Ni(2) atoms. There are two inequivalent Co sites. In the first Co site, Co(1) is bonded to one Er(1), one Er(2), two equivalent Co(1), four equivalent Co(2), two equivalent Ni(1), and two equivalent Ni(2) atoms to form distorted CoEr2Co6Ni4 cuboctahedra that share corners with four equivalent Ni(2)Er2Co8Ni2 cuboctahedra, corners with eight equivalent Co(2)Er3Co6Ni3 cuboctahedra, corners with twelve equivalent Co(1)Er2Co6Ni4 cuboctahedra,  an edgeedge with one Co(1)Er2Co6Ni4 cuboctahedra, edges with two equivalent Co(2)Er3Co6Ni3 cuboctahedra, edges with two equivalent Ni(2)Er2Co8Ni2 cuboctahedra, faces with four equivalent Ni(2)Er2Co8Ni2 cuboctahedra, faces with seven equivalent Co(1)Er2Co6Ni4 cuboctahedra, and faces with ten equivalent Co(2)Er3Co6Ni3 cuboctahedra. In the second Co site, Co(2) is bonded to one Er(2), two equivalent Er(1), two equivalent Co(2), four equivalent Co(1), one Ni(1), and two equivalent Ni(2) atoms to form distorted CoEr3Co6Ni3 cuboctahedra that share corners with five equivalent Ni(2)Er2Co8Ni2 cuboctahedra, corners with eight equivalent Co(1)Er2Co6Ni4 cuboctahedra, corners with ten equivalent Co(2)Er3Co6Ni3 cuboctahedra, edges with two equivalent Co(1)Er2Co6Ni4 cuboctahedra, edges with three equivalent Ni(2)Er2Co8Ni2 cuboctahedra, edges with five equivalent Co(2)Er3Co6Ni3 cuboctahedra, faces with two equivalent Ni(2)Er2Co8Ni2 cuboctahedra, faces with eight equivalent Co(2)Er3Co6Ni3 cuboctahedra, and faces with ten equivalent Co(1)Er2Co6Ni4 cuboctahedra. There are two inequivalent Ni sites. In the first Ni site, Ni(2) is bonded to two equivalent Er(2), four equivalent Co(1), four equivalent Co(2), and two equivalent Ni(1) atoms to form NiEr2Co8Ni2 cuboctahedra that share corners with four equivalent Ni(2)Er2Co8Ni2 cuboctahedra, corners with eight equivalent Co(1)Er2Co6Ni4 cuboctahedra, corners with ten equivalent Co(2)Er3Co6Ni3 cuboctahedra, edges with four equivalent Co(1)Er2Co6Ni4 cuboctahedra, edges with six equivalent Co(2)Er3Co6Ni3 cuboctahedra, faces with four equivalent Co(2)Er3Co6Ni3 cuboctahedra, faces with six equivalent Ni(2)Er2Co8Ni2 cuboctahedra, and faces with eight equivalent Co(1)Er2Co6Ni4 cuboctahedra. In the second Ni site, Ni(1) is bonded in a 14-coordinate geometry to one Er(2), three equivalent Co(2), six equivalent Co(1), one Ni(1), and three equivalent Ni(2) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_Er2Co12Ni5
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.049
_cell_length_b   8.287
_cell_length_c   8.287
_cell_angle_alpha   120.007
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   478.593
_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  0.750  0.000  1.000  1.0
  Er  Er1  1  0.250  1.000  0.000  1.0
  Er  Er2  1  0.250  0.667  0.333  1.0
  Er  Er3  1  0.750  0.333  0.667  1.0
  Co  Co4  1  0.750  0.673  0.049  1.0
  Co  Co5  1  0.750  0.375  0.327  1.0
  Co  Co6  1  0.750  0.951  0.625  1.0
  Co  Co7  1  0.750  0.375  0.049  1.0
  Co  Co8  1  0.750  0.951  0.327  1.0
  Co  Co9  1  0.750  0.673  0.625  1.0
  Co  Co10  1  0.250  0.327  0.951  1.0
  Co  Co11  1  0.250  0.625  0.673  1.0
  Co  Co12  1  0.250  0.049  0.375  1.0
  Co  Co13  1  0.250  0.625  0.951  1.0
  Co  Co14  1  0.250  0.049  0.673  1.0
  Co  Co15  1  0.250  0.327  0.375  1.0
  Co  Co16  1  0.476  0.838  0.675  1.0
  Co  Co17  1  0.476  0.838  0.162  1.0
  Co  Co18  1  0.476  0.325  0.162  1.0
  Co  Co19  1  0.524  0.162  0.325  1.0
  Co  Co20  1  0.524  0.162  0.838  1.0
  Co  Co21  1  0.524  0.675  0.838  1.0
  Co  Co22  1  0.976  0.162  0.325  1.0
  Co  Co23  1  0.976  0.162  0.838  1.0
  Co  Co24  1  0.976  0.675  0.838  1.0
  Co  Co25  1  0.024  0.838  0.675  1.0
  Co  Co26  1  0.024  0.838  0.162  1.0
  Co  Co27  1  0.024  0.325  0.162  1.0
  Ni  Ni28  1  0.599  0.667  0.333  1.0
  Ni  Ni29  1  0.401  0.333  0.667  1.0
  Ni  Ni30  1  0.099  0.333  0.667  1.0
  Ni  Ni31  1  0.901  0.667  0.333  1.0
  Ni  Ni32  1  0.500  0.500  0.000  1.0
  Ni  Ni33  1  0.500  0.500  0.500  1.0
  Ni  Ni34  1  0.500  0.000  0.500  1.0
  Ni  Ni35  1  0.000  0.500  0.000  1.0
  Ni  Ni36  1  0.000  0.500  0.500  1.0
  Ni  Ni37  1  0.000  0.000  0.500  1.0
[/CIF]
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The material structure described by Er2Co12Ni5 crystallizes in the hexagonal P6_3/mmc space group. There are two inequivalent Er sites. In the first Er site, Er(1) is bonded in a 18-coordinate geometry to six equivalent Co(1) and twelve equivalent Co(2) atoms. In the second Er site, Er(2) is bonded in a 20-coordinate geometry to six equivalent Co(1), six equivalent Co(2), two equivalent Ni(1), and six equivalent Ni(2) atoms. There are two inequivalent Co sites. In the first Co site, Co(1) is bonded to one Er(1), one Er(2), two equivalent Co(1), four equivalent Co(2), two equivalent Ni(1), and two equivalent Ni(2) atoms to form distorted CoEr2Co6Ni4 cuboctahedra that share corners with four equivalent Ni(2)Er2Co8Ni2 cuboctahedra, corners with eight equivalent Co(2)Er3Co6Ni3 cuboctahedra, corners with twelve equivalent Co(1)Er2Co6Ni4 cuboctahedra,  an edgeedge with one Co(1)Er2Co6Ni4 cuboctahedra, edges with two equivalent Co(2)Er3Co6Ni3 cuboctahedra, edges with two equivalent Ni(2)Er2Co8Ni2 cuboctahedra, faces with four equivalent Ni(2)Er2Co8Ni2 cuboctahedra, faces with seven equivalent Co(1)Er2Co6Ni4 cuboctahedra, and faces with ten equivalent Co(2)Er3Co6Ni3 cuboctahedra. In the second Co site, Co(2) is bonded to one Er(2), two equivalent Er(1), two equivalent Co(2), four equivalent Co(1), one Ni(1), and two equivalent Ni(2) atoms to form distorted CoEr3Co6Ni3 cuboctahedra that share corners with five equivalent Ni(2)Er2Co8Ni2 cuboctahedra, corners with eight equivalent Co(1)Er2Co6Ni4 cuboctahedra, corners with ten equivalent Co(2)Er3Co6Ni3 cuboctahedra, edges with two equivalent Co(1)Er2Co6Ni4 cuboctahedra, edges with three equivalent Ni(2)Er2Co8Ni2 cuboctahedra, edges with five equivalent Co(2)Er3Co6Ni3 cuboctahedra, faces with two equivalent Ni(2)Er2Co8Ni2 cuboctahedra, faces with eight equivalent Co(2)Er3Co6Ni3 cuboctahedra, and faces with ten equivalent Co(1)Er2Co6Ni4 cuboctahedra. There are two inequivalent Ni sites. In the first Ni site, Ni(2) is bonded to two equivalent Er(2), four equivalent Co(1), four equivalent Co(2), and two equivalent Ni(1) atoms to form NiEr2Co8Ni2 cuboctahedra that share corners with four equivalent Ni(2)Er2Co8Ni2 cuboctahedra, corners with eight equivalent Co(1)Er2Co6Ni4 cuboctahedra, corners with ten equivalent Co(2)Er3Co6Ni3 cuboctahedra, edges with four equivalent Co(1)Er2Co6Ni4 cuboctahedra, edges with six equivalent Co(2)Er3Co6Ni3 cuboctahedra, faces with four equivalent Co(2)Er3Co6Ni3 cuboctahedra, faces with six equivalent Ni(2)Er2Co8Ni2 cuboctahedra, and faces with eight equivalent Co(1)Er2Co6Ni4 cuboctahedra. In the second Ni site, Ni(1) is bonded in a 14-coordinate geometry to one Er(2), three equivalent Co(2), six equivalent Co(1), one Ni(1), and three equivalent Ni(2) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_Er2Co12Ni5
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.049
_cell_length_b   8.287
_cell_length_c   8.287
_cell_angle_alpha   120.007
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   478.593
_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  0.750  0.000  1.000  1.0
  Er  Er1  1  0.250  1.000  0.000  1.0
  Er  Er2  1  0.250  0.667  0.333  1.0
  Er  Er3  1  0.750  0.333  0.667  1.0
  Co  Co4  1  0.750  0.673  0.049  1.0
  Co  Co5  1  0.750  0.375  0.327  1.0
  Co  Co6  1  0.750  0.951  0.625  1.0
  Co  Co7  1  0.750  0.375  0.049  1.0
  Co  Co8  1  0.750  0.951  0.327  1.0
  Co  Co9  1  0.750  0.673  0.625  1.0
  Co  Co10  1  0.250  0.327  0.951  1.0
  Co  Co11  1  0.250  0.625  0.673  1.0
  Co  Co12  1  0.250  0.049  0.375  1.0
  Co  Co13  1  0.250  0.625  0.951  1.0
  Co  Co14  1  0.250  0.049  0.673  1.0
  Co  Co15  1  0.250  0.327  0.375  1.0
  Co  Co16  1  0.476  0.838  0.675  1.0
  Co  Co17  1  0.476  0.838  0.162  1.0
  Co  Co18  1  0.476  0.325  0.162  1.0
  Co  Co19  1  0.524  0.162  0.325  1.0
  Co  Co20  1  0.524  0.162  0.838  1.0
  Co  Co21  1  0.524  0.675  0.838  1.0
  Co  Co22  1  0.976  0.162  0.325  1.0
  Co  Co23  1  0.976  0.162  0.838  1.0
  Co  Co24  1  0.976  0.675  0.838  1.0
  Co  Co25  1  0.024  0.838  0.675  1.0
  Co  Co26  1  0.024  0.838  0.162  1.0
  Co  Co27  1  0.024  0.325  0.162  1.0
  Ni  Ni28  1  0.599  0.667  0.333  1.0
  Ni  Ni29  1  0.401  0.333  0.667  1.0
  Ni  Ni30  1  0.099  0.333  0.667  1.0
  Ni  Ni31  1  0.901  0.667  0.333  1.0
  Ni  Ni32  1  0.500  0.500  0.000  1.0
  Ni  Ni33  1  0.500  0.500  0.500  1.0
  Ni  Ni34  1  0.500  0.000  0.500  1.0
  Ni  Ni35  1  0.000  0.500  0.000  1.0
  Ni  Ni36  1  0.000  0.500  0.500  1.0
  Ni  Ni37  1  0.000  0.000  0.500  1.0
[/CIF]
.