#\#CIF_2.0
# Created by the Bilbao Crystallographic Server
# http://www.cryst.ehu.es
# Date: 11/19/2017 17:10:10
# Database entry: 1.64 BaNiF4
# Cif-like file for the case 1.64


data_5yOhtAoR
_audit_creation_date            2017-11-19
_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                    'Ba Ni F4'
_chemical_formula_weight                 ?
_chemical_melting_point                  ?
_chemical_compound_source                ?
_chemical_absolute_configuration         .


_citation_journal_abbrev        "J. Applied Phys."
_citation_journal_volume        41
_citation_page_first            943
_citation_page_last             ?
_citation_article_id            .
_citation_year                  1970
_citation_DOI                   10.1063/1.1659035

loop_
_citation_author_name
"D.E. Cox"
"M. Eibschutz"
"H.J. Guggenheim"
"L. Holmes"





_atomic_positions_source_database_code_ICSD   23141
_atomic_positions_source_other               .

_transition_temperature     ?
_experiment_temperature     4.2

loop_
_irrep_id
_irrep_dimension
_irrep_small_dimension
_irrep_direction_type
_irrep_action
_irrep_modes_number
_irrep_presence
mS2 2 1 . primary . .

_exptl_crystal_magnetic_properties_details
;
A small canting caused by a non-zero mz component has been reported in Ederer et al., PHYSICAL REVIEW B 74, 020401R 2006.
Ferroelectric parent phase. Multiferroic
Virtual parent paraelectric phase with Cmcm space group
;

_active_magnetic_irreps_details
;
1k magnetic structure
k-maximal magnetic symmetry (2 possible).
when considered from the parent Cmcm symmetry, the  weak mz component is a secondary irrep component, which is switchable with the polarization.
The allowed mz component is caused by the structural polar distortion reducing the symmetry to Cmc21.
;

_parent_space_group.name_H-M_alt  'C  m  c  2_1'
_parent_space_group.IT_number                       36
_parent_space_group.transform_Pp_abc  'a,b,c;0,0,0'

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

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


_space_group_magn.number_BNS  4.10
_space_group_magn.name_BNS  "P_a  2_1"
_space_group_magn.point_group_name  "21'"
_space_group_magn.point_group_number  "3.2.7"
_cell_length_a                 8.27800
_cell_length_b                 28.73800
_cell_length_c                 5.77500
_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

loop_
_space_group_symop_magn_centering.id
_space_group_symop_magn_centering.xyz
1 x,y,z,+1
2 x+1/4,y+3/4,z,+1
3 x+1/2,y+1/2,z,+1
4 x+3/4,y+1/4,z,+1
5 x+1/4,y+1/4,z,-1
6 x+1/2,y,z,-1
7 x+3/4,y+3/4,z,-1
8 x,y+1/2,z,-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 Ba 0.00000 0.07350 0.96300 1
Ni1 Ni2+ 0.00000 0.20700 0.00000 1
F1 F 0.00000 0.23750 0.28700 1
F2 F 0.00000 0.15000 0.20100 1
F3 F 0.00000 0.16450 0.74500 1
F4 F 0.00000 0.45850 0.02300 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
Ni1 0.0 2. 0.0 mx,my,mz

