#\#CIF_2.0
# Created by the Bilbao Crystallographic Server
# http://www.cryst.ehu.es
# Date: 20/03/2021 

data_5yOhtAoR
_audit_creation_date            2021-03-20
_audit_creation_method          "Bilbao Crystallographic Server"

_citation_journal_abbrev        "Solid State Communications"
_citation_journal_volume        8
_citation_page_first            1001
_citation_page_last             1005
_citation_article_id            .
_citation_year                  1970
_citation_DOI                   10.1016/0038-1098(70)90505-3

loop_
_citation_author_name
"V. J. Minkiewicz"
"D. E. Cox"
"G. Shirane"

_atomic_positions_source_database_code_ICSD  60261
_atomic_positions_source_other               .

_transition_temperature  11
_experiment_temperature  5.13

loop_
_irrep_id
_irrep_dimension
_irrep_small_dimension
_irrep_direction_type
_irrep_action
_irrep_modes_number
_irrep_presence
mK3  2  1  special  primary  1  .
mK5  4  2  special  primary  1  .
mGM4+ 1  1  .  secondary 1  no
mGM6+ 2 2  special secondary 1 no
mK4  2  1  special secondary 1  no
mK6  4 2   special secondary 1  no

_exptl_crystal_magnetic_properties_details
;
NPD and NSD
Improved models were published later
The direction of the spin basal component is undetermined. The one chosen in this paper, namely (1,2,0) corresponds to a maximal symmetry. The other non-equivalent direction that maximizes the symmetry is (1,1,0) (or equivalent), which implies a different MSG: Cm'c2_1' (N. 36.174). This alternative direction is the one chosen in a modified model of the structure (see  #1.0.34).
Although these two alternative models may be undistinguishable by NPD data, they are bound to exhibit quite different macroscopic properties: the Cm'c2_1' model is polar along c, which implies that some magnetically induced spontaneous polarization along this direction can exist, while the C22'2_1' model, reproduced here, is non-polar.
;

_active_magnetic_irreps_details
;
1k magnetic structure
Two irreps as primary, i.e. two order parameters in the sense of Landau theory are present. One for the spin arrangement along c and another one for the one on the basal plane. Sucessive distinct phase transitions very close in temperature, corresponding to these two different order parameters, have been reported later.
Four secondary irreps are symmetry-allowed, but are not present in the model.
See #1.0.34 for a model of this structure with a non-zero contribution of one of these secondary irrep components, which breaks the exact 120 degrees spin rotation assumed in the present structure.
Weak FM, corresponding to one of the secondary irreps is symmetry-allowed along the (1,2,0) direction.
;
 
_parent_space_group.name_H-M_alt  'P 6_3/m m c'
_parent_space_group.IT_number                       194
_parent_space_group.transform_Pp_abc  'a,b,c;0,0,0'

loop_
_parent_propagation_vector.id
_parent_propagation_vector.kxkykz
k1 [1/3 1/3 0]

_parent_space_group.child_transform_Pp_abc  '3a,3b,c;0,0,0'
_space_group_magn.transform_BNS_Pp_abc  '1/3a+2/3b,-a,c;0,0,1/4'



_space_group_magn.number_BNS  20.34
_space_group_magn.name_BNS  "C 2 2' 2_1'"
_cell_length_a             20.76000
_cell_length_b             20.76000
_cell_length_c             5.87000
_cell_angle_alpha          90.00
_cell_angle_beta           90.00
_cell_angle_gamma          120.00

loop_
_space_group_symop_magn_operation.id
_space_group_symop_magn_operation.xyz
1 x,y,z,+1 
2 -x+y,y,-z+1/2,+1 
3 x-y,-y,-z,-1 
4 -x,-y,z+1/2,-1 

loop_
_space_group_symop_magn_centering.id
_space_group_symop_magn_centering.xyz
1 x,y,z,+1 
2 x+1/3,y+2/3,z,+1 
3 x+2/3,y+1/3,z,+1 

loop_
_atom_site_label
_atom_site_type_symbol
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
Rb1_1 Rb 0.11111 0.22222 0.75000
Rb1_2 Rb  0.22222 0.11111 0.25000
Ni1_1 Ni 0.00000 0.00000 0.00000
Ni1_2 Ni  0.00000 0.33333 0.00000
Ni1_3 Ni  0.00000 0.66667 0.00000
Cl1_1 Cl 0.05333 0.10666 0.25000
Cl1_2 Cl  0.89333 0.94667 0.25000
Cl1_3 Cl  0.05333 0.44000 0.25000
Cl1_4 Cl  0.89333 0.28000 0.25000
Cl1_5 Cl  0.05333 0.28000 0.25000

loop_
_atom_site_moment.label
_atom_site_moment.crystalaxis_x
_atom_site_moment.crystalaxis_y
_atom_site_moment.crystalaxis_z
_atom_site_moment.symmform
_atom_site_moment.magnitude
Ni1_1 0.00000 0.00000 -1.50(15) mx,2mx,mz  1.50(15)
Ni1_2 0.75 1.50 0.75 mx,2mx,mz  1.50
Ni1_3 -0.75 -1.50 0.75 mx,2mx,mz  1.50

