#\#CIF_2.0
# Created by the Bilbao Crystallographic Server
# http://www.cryst.ehu.es
# Date: 01/05/2022

data_5yOhtAoR
_audit_creation_date            2022-01-05
_audit_creation_method          "Bilbao Crystallographic Server"

_chemical_name_systematic
;
;
_chemical_name_common                    ?
_chemical_formula_moiety                 ?
_chemical_formula_structural             ?
_chemical_formula_analytical             ?
_chemical_formula_iupac                  ?
_chemical_formula_sum                    "Ba2 Fe Si2 O7"
_chemical_formula_weight                 ?
_chemical_melting_point                  ?
_chemical_compound_source                ?
_chemical_absolute_configuration         ?


_citation_journal_abbrev        "PHYSICAL REVIEW B"
_citation_journal_volume        104
_citation_page_first            .
_citation_page_last             .
_citation_article_id            214434
_citation_year                  2021
_citation_DOI                   10.1103/PhysRevB.104.214434

loop_
_citation_author_name
"T.-H. Jang"
"S.-H. Do"
"M. Lee"
"H. Wu"
"C. M. Brown"
"A. D. Christianson"
"S.-W. Cheong"
"J.-H. Park"

_temperature_position_structure         .
_temperature_atom_positions             .
_temperature_non-magn_atom_positions    .
_temperature_cell_parameters            .

_atomic_positions_source_database_code_ICSD  .
_atomic_positions_source_other               .

_transition_temperature     5.2
_experiment_temperature     1.7

loop_
_irrep_id
_irrep_dimension
_irrep_small_dimension
_irrep_direction_type
_irrep_action
_irrep_modes_number
_irrep_presence
mZ5 2 2 special primary 2 ?

_exptl_crystal_magnetic_properties_details
;
NPD
Probably the direction of the moments on the ab plane is undetermined and the direction proposed in the paper, which corresponds to a maximal MSG was chosen arbitrarily.
Moment components are given here with non-significant digits to be consistent with the reported moment modulus.
;

_active_magnetic_irreps_details
;
1k magnetic structure
k-maximal magnetic symmetry
2-dim irrep along a special direction
The MSG is polar along c
;

_parent_space_group.name_H-M_alt  'P -4 2_1 m'
_parent_space_group.IT_number                       113
_parent_space_group.transform_Pp_abc  'a,b,c;0,0,0'

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

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

_space_group_magn.number_BNS  36.177
_space_group_magn.name_BNS  "C_c m c 2_1"
_space_group_magn.point_group_name  "mm21'"
_space_group_magn.point_group_number  "7.2.21"
_cell_length_a                 8.31940
_cell_length_b                 8.31940
_cell_length_c                 10.66720
_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,z+1/2,+1 
3 y+1/2,x+1/2,z,+1 
4 -y+1/2,-x+1/2,z+1/2,+1 

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

loop_
_atom_site_label
_atom_site_type_symbol
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
_atom_site_occupancy
Ba1_1 Ba 0.16440 0.66440 0.25490 1
Ba1_2 Ba 0.66440 0.83560 0.74510 1
Fe1 Fe 0.00000 0.00000 0.00000 1
Si1_1 Si 0.36450 0.86450 0.48045 1
Si1_2 Si 0.86450 0.63550 0.51955 1
O1_1 O 0.00000 0.50000 0.06915 1
O1_2 O 0.50000 0.00000 0.93085 1
O2_1 O 0.36510 0.86510 0.13210 1
O2_2 O 0.86510 0.63490 0.86790 1
O3_1 O 0.07690 0.19840 0.08470 1
O3_2 O 0.19840 0.92310 0.91530 1

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
_atom_site_moment.spherical_azimuthal
_atom_site_moment.spherical_polar
Fe1 2.085 2.085 0.0 mx,my,0 2.95 ? ?

