The material described by Er2Ni12As7 crystallizes in the hexagonal P-6 space group. There are two inequivalent Er sites. In the first Er site, Er(1) is bonded in a 15-coordinate geometry to three equivalent Ni(3), six equivalent Ni(1), and six equivalent As(2) atoms. In the second Er site, Er(2) is bonded in a 18-coordinate geometry to three equivalent Ni(1), three equivalent Ni(2), six equivalent Ni(3), and six equivalent As(3) atoms. There are four inequivalent Ni sites. In the first Ni site, Ni(1) is bonded in a 4-coordinate geometry to one Er(2), two equivalent Er(1), two equivalent As(2), and two equivalent As(3) atoms. In the second Ni site, Ni(2) is bonded to one Er(2), one As(1), one As(2), and two equivalent As(3) atoms to form distorted NiErAs4 tetrahedra that share corners with two equivalent Ni(3)Er3As4 tetrahedra, corners with six equivalent Ni(2)ErAs4 tetrahedra, edges with two equivalent Ni(3)Er3As4 tetrahedra, and faces with two equivalent Ni(3)Er3As4 tetrahedra. In the third Ni site, Ni(3) is bonded to one Er(1), two equivalent Er(2), two equivalent As(2), and two equivalent As(3) atoms to form distorted NiEr3As4 tetrahedra that share corners with two equivalent Ni(2)ErAs4 tetrahedra, corners with six equivalent Ni(3)Er3As4 tetrahedra, edges with two equivalent Ni(3)Er3As4 tetrahedra, edges with two equivalent Ni(2)ErAs4 tetrahedra, faces with two equivalent Ni(3)Er3As4 tetrahedra, and faces with two equivalent Ni(2)ErAs4 tetrahedra. In the fourth Ni site, Ni(4) is bonded in a 5-coordinate geometry to one As(3), two equivalent As(1), and two equivalent As(2) atoms. There are three inequivalent As sites. In the first As site, As(1) is bonded in a 9-coordinate geometry to three equivalent Ni(2) and six equivalent Ni(4) atoms. In the second As site, As(2) is bonded in a 9-coordinate geometry to two equivalent Er(1), one Ni(2), two equivalent Ni(1), two equivalent Ni(3), and two equivalent Ni(4) atoms. In the third As site, As(3) is bonded in a 9-coordinate geometry to two equivalent Er(2), one Ni(4), two equivalent Ni(1), two equivalent Ni(2), and two equivalent Ni(3) atoms. is represented by the CIF card [CIF]
data_Er2Ni12As7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.274
_cell_length_b   9.274
_cell_length_c   3.786
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   119.993
_symmetry_Int_Tables_number   1
_cell_volume   281.996
_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  0.667  0.333  0.500  1.0
  Er  Er1  1  0.333  0.667  0.000  1.0
  Ni  Ni2  1  0.438  0.058  0.000  1.0
  Ni  Ni3  1  0.620  0.562  0.000  1.0
  Ni  Ni4  1  0.942  0.380  0.000  1.0
  Ni  Ni5  1  0.151  0.280  0.000  1.0
  Ni  Ni6  1  0.129  0.849  0.000  1.0
  Ni  Ni7  1  0.720  0.871  0.000  1.0
  Ni  Ni8  1  0.376  0.426  0.500  1.0
  Ni  Ni9  1  0.050  0.624  0.500  1.0
  Ni  Ni10  1  0.574  0.950  0.500  1.0
  Ni  Ni11  1  0.211  0.095  0.500  1.0
  Ni  Ni12  1  0.884  0.789  0.500  1.0
  Ni  Ni13  1  0.905  0.116  0.500  1.0
  As  As14  1  0.000  1.000  0.000  1.0
  As  As15  1  0.405  0.288  0.000  1.0
  As  As16  1  0.883  0.595  0.000  1.0
  As  As17  1  0.712  0.117  0.000  1.0
  As  As18  1  0.110  0.408  0.500  1.0
  As  As19  1  0.298  0.890  0.500  1.0
  As  As20  1  0.592  0.702  0.500  1.0
[/CIF]
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The material described by Er2Ni12As7 crystallizes in the hexagonal P-6 space group. There are two inequivalent Er sites. In the first Er site, Er(1) is bonded in a 15-coordinate geometry to three equivalent Ni(3), six equivalent Ni(1), and six equivalent As(2) atoms. In the second Er site, Er(2) is bonded in a 18-coordinate geometry to three equivalent Ni(1), three equivalent Ni(2), six equivalent Ni(3), and six equivalent As(3) atoms. There are four inequivalent Ni sites. In the first Ni site, Ni(1) is bonded in a 4-coordinate geometry to one Er(2), two equivalent Er(1), two equivalent As(2), and two equivalent As(3) atoms. In the second Ni site, Ni(2) is bonded to one Er(2), one As(1), one As(2), and two equivalent As(3) atoms to form distorted NiErAs4 tetrahedra that share corners with two equivalent Ni(3)Er3As4 tetrahedra, corners with six equivalent Ni(2)ErAs4 tetrahedra, edges with two equivalent Ni(3)Er3As4 tetrahedra, and faces with two equivalent Ni(3)Er3As4 tetrahedra. In the third Ni site, Ni(3) is bonded to one Er(1), two equivalent Er(2), two equivalent As(2), and two equivalent As(3) atoms to form distorted NiEr3As4 tetrahedra that share corners with two equivalent Ni(2)ErAs4 tetrahedra, corners with six equivalent Ni(3)Er3As4 tetrahedra, edges with two equivalent Ni(3)Er3As4 tetrahedra, edges with two equivalent Ni(2)ErAs4 tetrahedra, faces with two equivalent Ni(3)Er3As4 tetrahedra, and faces with two equivalent Ni(2)ErAs4 tetrahedra. In the fourth Ni site, Ni(4) is bonded in a 5-coordinate geometry to one As(3), two equivalent As(1), and two equivalent As(2) atoms. There are three inequivalent As sites. In the first As site, As(1) is bonded in a 9-coordinate geometry to three equivalent Ni(2) and six equivalent Ni(4) atoms. In the second As site, As(2) is bonded in a 9-coordinate geometry to two equivalent Er(1), one Ni(2), two equivalent Ni(1), two equivalent Ni(3), and two equivalent Ni(4) atoms. In the third As site, As(3) is bonded in a 9-coordinate geometry to two equivalent Er(2), one Ni(4), two equivalent Ni(1), two equivalent Ni(2), and two equivalent Ni(3) atoms. is represented by the CIF card [CIF]
data_Er2Ni12As7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.274
_cell_length_b   9.274
_cell_length_c   3.786
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   119.993
_symmetry_Int_Tables_number   1
_cell_volume   281.996
_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  0.667  0.333  0.500  1.0
  Er  Er1  1  0.333  0.667  0.000  1.0
  Ni  Ni2  1  0.438  0.058  0.000  1.0
  Ni  Ni3  1  0.620  0.562  0.000  1.0
  Ni  Ni4  1  0.942  0.380  0.000  1.0
  Ni  Ni5  1  0.151  0.280  0.000  1.0
  Ni  Ni6  1  0.129  0.849  0.000  1.0
  Ni  Ni7  1  0.720  0.871  0.000  1.0
  Ni  Ni8  1  0.376  0.426  0.500  1.0
  Ni  Ni9  1  0.050  0.624  0.500  1.0
  Ni  Ni10  1  0.574  0.950  0.500  1.0
  Ni  Ni11  1  0.211  0.095  0.500  1.0
  Ni  Ni12  1  0.884  0.789  0.500  1.0
  Ni  Ni13  1  0.905  0.116  0.500  1.0
  As  As14  1  0.000  1.000  0.000  1.0
  As  As15  1  0.405  0.288  0.000  1.0
  As  As16  1  0.883  0.595  0.000  1.0
  As  As17  1  0.712  0.117  0.000  1.0
  As  As18  1  0.110  0.408  0.500  1.0
  As  As19  1  0.298  0.890  0.500  1.0
  As  As20  1  0.592  0.702  0.500  1.0
[/CIF]
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