#\#CIF_2.0
# Created by the Bilbao Crystallographic Server
# http://www.cryst.ehu.es
# Date: 12/04/2020

data_5yOhtAoR
_audit_creation_date            2020-04-12
_audit_creation_method          "Bilbao Crystallographic Server"

_citation_journal_abbrev        "Physical Review"
_citation_journal_volume        122
_citation_page_first            1402
_citation_page_last             1406
_citation_article_id            ?
_citation_year                  1961
_citation_DOI                   10.1103/PhysRev.122.1402

loop_
_citation_author_name
"L.M. Corliss"
"N. Elliott"
"J.M. Hastings"
"R.L. Sass"




_atomic_positions_source_database_code_ICSD  626717
_atomic_positions_source_other               .

_transition_temperature  300
_experiment_temperature  4.2


loop_
_irrep_id
_irrep_dimension
_irrep_small_dimension
_irrep_direction_type
_irrep_action
_irrep_modes_number
_irrep_presence
mK5  4  2  special  primary  1  .
mGM4+ 1  1  .   primary    1   .
mK6 4  2   special secondary  1  no
mGM2+ 1  1   .   secondary  1    no

_exptl_crystal_magnetic_properties_details
;
NPD
Position structure from a determination at room temperature (icsd)
Only the z component of the Cr moment was determined, the component on the basal plane is estimated assuming a total moment agrreeing with the theoretical value of 4 muB.
;

_active_magnetic_irreps_details
;
1k magnetic structure
Two primary irreps with wavevectors (1/3,1/3,0) and (0,0,0) are present, which implies that two order parameters are involved
The second primary irrep corresponds to a k=0 arrangement of the z spin components, which is not however a third harmonc of the primary mK5 modulation, and it breaks further the system symmetry.
Secondary irreps are symmtry allowed, but are not present in the model.
The structure is proposed using ad-hoc arguments. It seems that possible alternative simpler models with a single primary irrep were not systematically crosschecked.
;

_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]
k2 [0 0 0]

_parent_space_group.child_transform_Pp_abc  'a-b,a+2b,c;0,0,0'
_space_group_magn.transform_BNS_Pp_abc  'a+b,-a,c;2/3,5/3,0'



_space_group_magn.number_BNS  157.55
_space_group_magn.name_BNS  "P 3 1 m'"
_cell_length_a             6.37390
_cell_length_b             6.37390
_cell_length_c             6.02000
_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 -y+1/3,x-y+2/3,z,+1
3 -x+y+2/3,-x+1/3,z,+1
4 x-y+2/3,-y+1/3,z,-1
5 y,x,z,-1
6 -x+1/3,-x+y+2/3,z,-1

loop_
_space_group_symop_magn_centering.id
_space_group_symop_magn_centering.xyz
1 x,y,z,+1

loop_
_atom_site_label
_atom_site_type_symbol
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
Cr1_1 Cr 0.00000 0.00000 0.00000
Cr1_2 Cr 0.00000 0.00000 0.50000
Se1_1 Se 0.00000 0.33333 0.25000
Se1_2 Se 0.33333 0.33333 0.75000
Se1_3 Se 0.66666 0.66667 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
Cr1_1 -1.95 -1.95 -2.90 mx,mx,mz
Cr1_2 1.95 1.95 2.90 mx,mx,mz

