#\#CIF_2.0
# Created by the Bilbao Crystallographic Server
# http://www.cryst.ehu.es
# Date: 22/04/2020 

data_5yOhtAoR
_audit_creation_date            2020-04-22
_audit_creation_method          "Bilbao Crystallographic Server"

_citation_journal_abbrev        "J. Phys. Chem. Solids"
_citation_journal_volume        28
_citation_page_first            2143
_citation_page_last             2154
_citation_article_id            ?
_citation_year                  1967
_citation_DOI                   10.1016/0038-1098(67)90276-1

loop_
_citation_author_name
"E.F. Bertaut"
"J. Mareschal"
"G.F. De Vries"

_atomic_positions_source_database_code_ICSD  .
_atomic_positions_source_other               .

_transition_temperature  3.05(5)
_experiment_temperature  1.5

loop_
_irrep_id
_irrep_dimension
_irrep_small_dimension
_irrep_direction_type
_irrep_action
_irrep_modes_number
_irrep_presence
mX2  2  2  special  primary  7  .
mGM2+ 1  1   .     primary   5  .
mGM1- 1  1   .     secondary 2  no


_exptl_crystal_magnetic_properties_details
;
NPD
Position structure from a determination at room temperature
Non-standard setting Pbnm of the parent space group
Lower temperature phase where the Tb moments order with an additional symmetry breaking.  Cr moments order at 158K (see #0.354)
; 

_active_magnetic_irreps_details
;
2k magnetic structure
Two irreps involved as primary: two order parameters in the sense of Landau theory
The two order parameters correspond to the Fe and Tb magnetic ordering. The Tb moments order according to the 2-dim k=(0,1/2,0) irrep along a special direction, while the Fe continues with its k=0 irrep ordering from the phase at higher temperatures (see #0.354)
The MSG allows a secondary irrep mode, which has zero amplitude in the model.
Both FM and polar along a (Pbnm parent setting).
;

_parent_space_group.name_H-M_alt  "P b n m"
_parent_space_group.IT_number                       62
_parent_space_group.transform_Pp_abc  'b,c,a;0,0,0'

loop_
_parent_propagation_vector.id
_parent_propagation_vector.kxkykz
k1 [0 1/2 0]
k2 [0 0 0]

_parent_space_group.child_transform_Pp_abc  'a,2b,c;0,0,0'
_space_group_magn.transform_BNS_Pp_abc  'c,-b,a;0,7/8,1/4'



_space_group_magn.number_BNS  31.127
_space_group_magn.name_BNS  "P m' n' 2_1"
_cell_length_a             5.291
_cell_length_b             11.026
_cell_length_c             7.557
_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+1/2,-y+3/4,-z,+1 
3 x,y,-z+1/2,-1 
4 x+1/2,-y+3/4,z+1/2,-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
Tb1_1 Tb 0.98900 0.03200 0.25000
Tb1_2 Tb 0.48900 0.21800 0.75000
Tb1_3 Tb 0.01100 0.96800 0.75000
Tb1_4 Tb 0.51100 0.28200 0.25000
Cr1_1 Cr 0.50000 0.00000 0.00000
Cr1_2 Cr 0.00000 0.25000 0.00000
O1_1 O 0.09600 0.23500 0.25000
O1_2 O 0.59600 0.01500 0.75000
O1_3 O 0.90400 0.76500 0.75000
O1_4 O 0.40400 0.48500 0.25000
O2_1 O 0.69700 0.15050 0.04900
O2_2 O 0.19700 0.09950 0.95100
O2_3 O 0.30300 0.84950 0.54900
O2_4 O 0.80300 0.40050 0.45100

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
Tb1_1 7.76 3.17 0.00000 mx,my,0       8.38
Tb1_2 -7.76 3.17 0.00000 mx,my,0      8.38
Tb1_3 -7.76 -3.17 0.00000 mx,my,0     8.38
Tb1_4 7.76 -3.17 0.00000 mx,my,0      8.38
Cr1_1 0.00000 0.00000 2.85 mx,my,mz   2.85
Cr1_2 0.00000 0.00000 -2.85 mx,my,mz  2.85

