#\#CIF_2.0
# Created by the Bilbao Crystallographic Server
# http://www.cryst.ehu.es
# Date: 11/30/2017 16:46:03
# Database entry: 1.1.25 LiFeAs2O7
# Cif-like file for the case 1.1.25


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                    'Li Fe As2 O7'
_chemical_formula_weight                 ?
_chemical_melting_point                  ?
_chemical_compound_source                ?
_chemical_absolute_configuration         .


_citation_journal_abbrev        "PHYSICAL REVIEW B"
_citation_journal_volume        88
_citation_page_first            ?
_citation_page_last             ?
_citation_article_id            214433
_citation_year                  2013
_citation_DOI                   10.1103/PhysRevB.88.214433

loop_
_citation_author_name
"G. Rousse"
"J. Rodriguez-Carvajal"
"C. Wurm"
"C. Masquelier"




_atomic_positions_source_database_code_ICSD  .
_atomic_positions_source_other               .

_transition_temperature     35
_experiment_temperature     2

loop_
_irrep_id
_irrep_dimension
_irrep_small_dimension
_irrep_direction_type
_irrep_action
_irrep_modes_number
_irrep_presence
? ? ? ? ? ? ?

_exptl_crystal_magnetic_properties_details
;
NPD
atomic positions from room temperature measurement.
Fe mooment modulus: 4.28(3)
;

_active_magnetic_irreps_details
;
The arbitrary phase of the modulation is chosen by fixing the z sine component of the Fe spin modulation to be zero.
The vector amplitude of the cosine modulation component is nearly perpendicular to the one of the sine modulation so that the modulation only rotates the moment without changing its modulus. This is not symmetry forced.
The spins rotate on a plane given by a rather arbitrary direction. The fit cannot distinguish between two models with with different orientation of the spin rotation plane. This is the first of the two models.
A single (irrep) mode (even if only one single irrep exists) would force this rotation plane to contain the monoclinic axis and the point-group symmetry would then keep the binary axis, the corresponding MSSG being monoclinic.
The reason why the higher symmetry corresponding to a single irrep mode is not realized is not clear (a single phase transition is reported).
;

_parent_space_group.name_H-M_alt              'C 2'
_parent_space_group.IT_number             5
_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 0.709000 0.000000 0.155000


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

_space_group.magn_ssg_name  "C11'(\a\b\g)0s"
_space_group.magn_point_group_name  "11'"
_space_group.magn_point_group_number  "1.2.2"
_cell_length_a                 6.6786(1)
_cell_length_b                 8.2855(1)
_cell_length_c                 4.7429(1)
_cell_angle_alpha              90
_cell_angle_beta               103.950(1)
_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

loop_
_space_group_symop_magn_ssg_centering.id
_space_group_symop_magn_ssg_centering.algebraic
1 x1,x2,x3,x4,+1
2 x1+1/2,x2+1/2,x3,x4,+1
3 x1,x2,x3,x4+1/2,-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
Li1 Li 0 0.617 0 1
Fe1 Fe 0 0 0 1
As1_1 As 0.7824 0.337 0.591 1
As1_2 As 0.21760 0.33700 0.409 1
O1_1 O 0.7497 0.4811 0.8237 1
O1_2 O 0.25030 0.48110 0.1763 1
O2_1 O 0.831 0.1567 0.7473 1
O2_2 O 0.16900 0.15670 0.2527 1
O3_1 O 0.61 0.317 0.2773 1
O3_2 O 0.39000 0.31700 0.72270 1
O4 O 0 0.4147 0.5 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 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
Fe1 x 1 -1.733 -1.672 mxc1 mxs1
Fe1 y 1 0.290 -3.939 myc1 mys1
Fe1 z 1 -4.343 0.0 mzc1 0.0


