#\#CIF_2.0
# Created by the Bilbao Crystallographic Server
# http://www.cryst.ehu.es
# Date: 24/04/2021 

data_5yOhtAoR
_audit_creation_date            2021-04-24
_audit_creation_method          "Bilbao Crystallographic Server"

_citation_journal_abbrev        "Solid State Communications"
_citation_journal_volume        63
_citation_page_first            65
_citation_page_last             67
_citation_article_id            .
_citation_year                  1987
_citation_DOI                   10.1016/0038-1098(87)90067-6

loop_
_citation_author_name
"T. Chattopadhyay"
"J. Rossat-Mignod"
"H. Fjellvag"

_atomic_positions_source_database_code_ICSD  12959
_atomic_positions_source_other               .

_transition_temperature  49
_experiment_temperature  1.8

loop_
_irrep_id
_irrep_dimension
_irrep_small_dimension
_irrep_direction_type
_irrep_action
_irrep_modes_number
_irrep_presence
mDT4  6  1  special  primary  3  .
mDT1  6  1  special  primary  3  .
mGM4  3  3  special  secondary 3 .

_exptl_crystal_magnetic_properties_details
;
NPD
Position structure used here is from another work at 293K.
;

_active_magnetic_irreps_details
;
1k magnetic structure
Two irreps involved as primary: two order parameters in the sense of Landau are involved
A secondary irrep corresponding to k=0 (third harmonic) is also present in the spin arrangement to produce a square-ike modulation.
This model requires a very specific relationship between the amplitudes of two order parameters associated with two different irreps. It is claimed to correct a previous one (see #1.0.47), which only involves a single order parameter (single primary irrep).
Polar along c
FM along b
;

_parent_space_group.name_H-M_alt  'P a -3'
_parent_space_group.IT_number                       205
_parent_space_group.transform_Pp_abc  'a,b,c;0,0,0'

loop_
_parent_propagation_vector.id
_parent_propagation_vector.kxkykz
k1 [1/3 0 0]
k2 [0 0 0]

_parent_space_group.child_transform_Pp_abc  '3a,b,c;0,0,0'
_space_group_magn.transform_BNS_Pp_abc  'b,-a,c;1/12,0,0'

_space_group_magn.number_BNS  29.102
_space_group_magn.name_BNS  "P c a' 2_1'"
_cell_length_a             19.28250
_cell_length_b             6.42750
_cell_length_c             6.42750
_cell_angle_alpha          90.00
_cell_angle_beta           90.00
_cell_angle_gamma          90.00

loop_
_space_group_symop_magn_operation.id
_space_group_symop_magn_operation.xyz
1 x,y,z,+1 
2 x,-y+1/2,z+1/2,+1 
3 -x+1/6,-y,z+1/2,-1 
4 -x+1/6,y+1/2,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
Mn1_1 Mn 0.00000 0.00000 0.00000
Mn1_2 Mn  0.33333 0.00000 0.00000
Mn1_3 Mn  0.50000 0.00000 0.50000
Se1_1 Se 0.13119 0.39357 0.39357
Se1_2 Se  0.86881 0.89358 0.10642
Se1_3 Se  0.46453 0.39358 0.39358
Se1_4 Se  0.36881 0.60642 0.89358
Se1_5 Se  0.20214 0.89358 0.10642
Se1_6 Se  0.63119 0.10642 0.60642

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
Mn1_1  2.8 0.0 0.0 mx,my,mz   2.8
Mn1_2 -2.8 0.0 0.0 mx,my,mz   2.8
Mn1_3 -2.8 0.0 0.0 mx,my,mz   2.8

