#\#CIF_2.0
# Created by the Bilbao Crystallographic Server
# http://www.cryst.ehu.es
# Date: 03/05/2020 19:49:53

data_5yOhtAoR
_audit_creation_date            2020-03-05
_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                    "Fe1 Ge2 Na1 O6"
_chemical_formula_weight                 ?
_chemical_melting_point                  ?
_chemical_compound_source                ?
_chemical_absolute_configuration         ?


_citation_journal_abbrev        "PHYSICAL REVIEW B"
_citation_journal_volume        98
_citation_page_first            ?
_citation_page_last             ?
_citation_article_id            094416
_citation_year                  2018
_citation_DOI                   10.1103/PhysRevB.98.094416

loop_
_citation_author_name
"L. Ding"
"P. Manuel"
"D.D. Khalyavin"
"F. Orlandi"
"A.A. Tsirlin"




_atomic_positions_source_database_code_ICSD  180310
_atomic_positions_source_other               .

_transition_temperature     11.6
_experiment_temperature     1.5

loop_
_irrep_id
_irrep_dimension
_irrep_small_dimension
_irrep_direction_type
_irrep_action
_irrep_modes_number
_irrep_presence
mB1 2 1 general primary ? .
mB1 2 1 general primary ? .

_exptl_crystal_magnetic_properties_details
;
NPD
Phase called ICM1, observed below 11.6K. Between 11.6K and 13K another incommensurate phase with higher centrosymmetry symmetry exists.
Positional structure retrieved from an icsd entry (180310) for the structure at 2.5K reported by a different work.
;

_active_magnetic_irreps_details
;
1k incommensurate magnetic structure
This structure requires two distinct order parameters, transforming according to the same irrep mB1, but with a phase shift between the two mB1 modulations. For the reported cycloidal form, this phase shift must be pi/2 (in quadrature).
The MSSG of the structure does not contain any operation transforming k into -k, and therefore, the phase origin of the modulation is not forced by the MSSG setting and can be set arbitrarily. Here it is chosen by setting the component mxs1 to zero.
Polar on the plane ac. Magnetically induced ferroelectricity on the ac plane (multiferroic of type II)
;

_parent_space_group.name_H-M_alt  "C 2/c"
_parent_space_group.IT_number             15
_parent_space_group.transform_Pp_abc  a,b,c;0,0,0

_cell_modulation_dimension               1

loop_
_cell_wave_vector_seq_id
_cell_wave_vector_x
_cell_wave_vector_y
_cell_wave_vector_z
1 -0.6702(1) 0.00000 0.08028(5)


_parent_space_group.child_transform_Pp_abc  a,b,c;0,0,0

_space_group.magn_ssg_name  "Cc1'(a,0,g)0s"
_space_group.magn_point_group_name  "m1'"
_space_group.magn_point_group_number  "4.2.10"
_cell_length_a                 9.99290
_cell_length_b                 8.91940
_cell_length_c                 5.51480
_cell_angle_alpha              90.00000
_cell_angle_beta               107.56300
_cell_angle_gamma              90.00000

loop_
_space_group_symop_magn_ssg_operation.id
_space_group_symop_magn_ssg_operation.algebraic
1 x1,x2,x3,x4,+1
2 x1,-x2,x3+1/2,x4,+1

loop_
_space_group_symop_magn_ssg_centering.id
_space_group_symop_magn_ssg_centering.algebraic
1 x1,x2,x3,x4,+1
2 x1,x2,x3,x4+1/2,-1
3 x1+1/2,x2+1/2,x3,x4,+1
4 x1+1/2,x2+1/2,x3,x4+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
Na1_1 Na 0.50000 0.80040 0.25000 1
Fe1_1 Fe 0.00000 -0.09620 0.25000 1
Ge1_1 Ge 0.78810 0.59390 0.22990 1
Ge1_2 Ge 0.21190 0.59390 0.27010 1
O1_1 O 0.60530 0.58070 0.13030 1
O1_2 O 0.39470 0.58070 0.36970 1
O2_1 O 0.85670 0.77150 0.29950 1
O2_2 O 0.14330 0.77150 0.20050 1
O3_1 O 0.86160 0.50700 0.01470 1
O3_2 O 0.13840 0.50700 0.48530 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
Fe1_1 0.00000 0.00000 0.00000 0,0,0

loop_
_atom_site_Fourier_wave_vector.seq_id
_atom_site_Fourier_wave_vector.q1_coeff
1 1

loop_
_atom_site_moment_Fourier.atom_site_label
_atom_site_moment_Fourier.axis
_atom_site_moment_Fourier.wave_vector_seq_id
_atom_site_moment_Fourier_param.cos
_atom_site_moment_Fourier_param.sin
_atom_site_moment_Fourier_param.cos_symmform
_atom_site_moment_Fourier_param.sin_symmform
Fe1_1 x 1 3.857(8) 0 mxc1 mxs1
Fe1_1 y 1 0 0 myc1 mys1
Fe1_1 z 1 0 3.857  mzc1 mzs1

