#\#CIF_2.0
# Created by the Bilbao Crystallographic Server
# http://www.cryst.ehu.es
# Date: 11/30/2017 16:46:01
# Database entry: 1.1.24 CrAs
# Cif-like file for the case 1.1.24


data_5yOhtAoR
_audit_creation_date            2017-11-30
_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                    'Cr As'
_chemical_formula_weight                 ?
_chemical_melting_point                  ?
_chemical_compound_source                ?
_chemical_absolute_configuration         .


_citation_journal_abbrev        "PHYSICAL REVIEW B"
_citation_journal_volume        91
_citation_page_first            ?
_citation_page_last             ?
_citation_article_id            020409(R)
_citation_year                  2015
_citation_DOI                   10.1103/PhysRevB.91.020409

loop_
_citation_author_name
"L. Keller"
"J.S. White"
"M. Frontzek"
"P. Babkevich"
"M.A. Susner"
"Z.C. Sims"
"A.S. Sefat"
"H.M. Ronnow"
"C. Ruegg"




_atomic_positions_source_database_code_ICSD  .
_atomic_positions_source_other               .

_transition_temperature     265
_experiment_temperature     1.5

loop_
_irrep_id
_irrep_dimension
_irrep_small_dimension
_irrep_direction_type
_irrep_action
_irrep_modes_number
_irrep_presence
mLD3 2 1 special primary 4 .
mLD4 2 1 special primary 2 .

_exptl_crystal_magnetic_properties_details
;
NPD
Model originally reported in Selte et al., Acta Chemica Scandinavica 25 (1971) 1703.
In the figure the modulation phase has been shifted to coincide with the choice done in the reference.
;

_active_magnetic_irreps_details
;
1k magnetic structure
Two irreps are combined in quadrature (origin shift pi/2 between the two irrep modulations).
Cr1 lies in a general position of the MSSG (mirror plane my is broken), and therefore its modulation has no symmetry-restriction.
The model constrains the  modulation to be an helical modulation on the ab plane (2 free parameters). A general spin model complying with the same magnetic symmetry allows 6 free parameters.
The spin modulation breaks the inversion center but the resulting point group 2221' remains non-polar.
;

_parent_space_group.name_H-M_alt              'P n m a'
_parent_space_group.IT_number             62
_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 0.000000 0.000000 0.356200


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

_space_group.magn_ssg_name  "P2121211'(00\g)00ss"
_space_group.magn_point_group_name  "2221'"
_space_group.magn_point_group_number  "6.2.18"
_cell_length_a                 5.65
_cell_length_b                 3.47
_cell_length_c                 6.203
_cell_angle_alpha              90
_cell_angle_beta               90
_cell_angle_gamma              90

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

loop_
_atom_site_label
_atom_site_type_symbol
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
_atom_site_occupancy
Cr1 Cr 0.0068(12) 0.25 0.2034(10) 1
As1 As 0.2011(10) 0.25 0.5802(12) 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 0 0 0 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 x 1 0.99 -1.42 mxc1 mxs1
Cr1 y 1 1.42 0.99 myc1 mys1
Cr1 z 1 0 0 mzc1 mzs1


