#\#CIF_2.0
# Created by the Bilbao Crystallographic Server
# http://www.cryst.ehu.es
# Date: 03/09/2021 

data_5yOhtAoR
_audit_creation_date            2021-03-09
_audit_creation_method          "Bilbao Crystallographic Server"

_citation_journal_abbrev        "JOURNAL OF SOLID STATE CHEMISTRY"
_citation_journal_volume        57
_citation_page_first            357
_citation_page_last             361
_citation_article_id            .
_citation_year                  1985
_citation_DOI                   10.1016/0022-4596(85)90199-9

loop_
_citation_author_name
"J. P. Attfield"
"P. D. Battle"
"A. K. Cheetham"

_atomic_positions_source_database_code_ICSD  62159
_atomic_positions_source_other               .

_transition_temperature     37
_experiment_temperature     5

loop_
_irrep_id
_irrep_dimension
_irrep_small_dimension
_irrep_direction_type
_irrep_action
_irrep_modes_number
_irrep_presence
mSM1 2 1 general primary 1 .
mSM4 2 1 special primary 2 .

_exptl_crystal_magnetic_properties_details
;
NPD
The observed propagation vector is incommensurate with value (0.326,0,0), and the paper fitted the data using a commensurate approximant with k=(1/3,0,0). Here we present the reported model with the actual incommensurate value for the propagation vector and its resulting symmetry, given by a MSSG
Value of the kx component of propagation vector is only approximate (estimatimated from a curve in the paper)
For a better comparison with the initial phase chosen in the paper and the graphical representation therein, the origin along x4 of the MSSG has been shifted with respect to the one that can be considered standard. 
;

_active_magnetic_irreps_details
;
1k incommensurate magnetic structure
two irreps as primary. They are shifted by pi/2 (in quadrature) to produce a cycloidal modulation
The spins rotate circularly on the xy plane, but the MSSG allows a more complex modulation with elliptical orbits their rotation plane being allowed to deviate from the ab plane, while keeping the a direction within the rotation plane.
The structure is polar along b, allowing for magnetically induced ferroelectricity (type II multiferroic)
;

_parent_space_group.name_H-M_alt  'C m c m
_parent_space_group.IT_number             63
_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 0.326 0.00000 0.00000


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

_space_group.magn_ssg_name  "Cm2m1'(a,0,0)000s"
_space_group.magn_point_group_name  "mm21'"
_space_group.magn_point_group_number  7.2.21
_cell_length_a                 5.17100
_cell_length_b                 7.75730
_cell_length_c                 6.11830
_cell_angle_alpha              90.00000
_cell_angle_beta               90.00000
_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+1/2,+1
3 -x1,x2,x3,-x4+1/2,+1
4 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
Cr1_1 Cr 0.00000 0.00000 0.00000 1
P1_1 P 0.00000 0.35030 0.25000 1
P1_2 P 0.00000 0.64970 0.75000 1
O1_1 O 0.00000 0.24590 0.04290 1
O1_2 O 0.00000 0.75410 -0.04290 1
O2_1 O 0.24620 0.47060 0.25000 1
O2_2 O 0.24620 0.52940 0.75000 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
Cr1_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
Cr1_1 x 1 0.00000 2.55 0 Mxs1
Cr1_1 y 1 -2.55(10) 0.00000 Myc1 0
Cr1_1 z 1 0.00000 0.00000 Mzc1 0

