#\#CIF_2.0
# Created by the Bilbao Crystallographic Server
# http://www.cryst.ehu.es
# Date: 11/14/2021 

data_5yOhtAoR
_audit_creation_date            2021-11-14
_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                    "Nd2 Cu O4"
_chemical_formula_weight                 ?
_chemical_melting_point                  ?
_chemical_compound_source                ?
_chemical_absolute_configuration         ?


_citation_journal_abbrev        "Physica C"
_citation_journal_volume        160
_citation_page_first            124
_citation_page_last             128
_citation_article_id            .
_citation_year                  1989
_citation_DOI                   10.1016/0921-4534(89)90180-9

loop_
_citation_author_name
"S. Skanthakumar"
"H. Zhang"
"T. W. Clinton"
"W-H. Li"
"J. W. Lynn"
"Z. Fisk"
"S.-W. Cheong"

_temperature_position_structure         0.5
_temperature_atom_positions             .
_temperature_non-magn_atom_positions    .
_temperature_cell_parameters            .

_atomic_positions_source_database_code_ICSD  69886
_atomic_positions_source_other               .

_transition_temperature     245
_experiment_temperature     78

loop_
_irrep_id
_irrep_dimension
_irrep_small_dimension
_irrep_direction_type
_irrep_action
_irrep_modes_number
_irrep_presence
mX4+ 2 1 special-2 primary 2 .

_exptl_crystal_magnetic_properties_details
;
Polarized and unpolarized NSD 
Positional structure, including cell parameters, is not specified. Here the structure determined at 0.5K by another atudy and retrieved from the ICSD is used.
There are two alternative physically distinct tetragonal MSGs, which are possible for this 2k structure, depending on the active irrep. They correspond to the two possible senses of rotation of spins (+pi/2 or -pi/2) in consecutive layers along the c axis. In the present case the spin arrangement is the same as the one proposed for Pr2CuO4, i.e. same MSG, same irrep (see #2.48), but differs from that reported for Sm2CuO4, i.e. different MSG, different irrep (see #2.7).
The paper reports at 75K a reorientation of the spins so that the rotation of spins in consecutive layers changes from +pi/2 or -pi/2, implying a transition into the other possible MSG mentioned above, reported for Sm2CuO4. The paper reports at 30K a new transitions with the system coming back into the spin arrangement described above 75K. 
;

_active_magnetic_irreps_details
;
2k magnetic structure
2-dim full irrep along a special direction.
;

_parent_space_group.name_H-M_alt  'I 4/m m m'
_parent_space_group.IT_number                       139
_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]
k2 [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,-1/2a+1/2b,c;1/4,1/4,0'

_space_group_magn.number_BNS  134.481
_space_group_magn.name_BNS  "P_C 4_2/n n m"
_space_group_magn.point_group_name  "4/mmm1'"
_space_group_magn.point_group_number  "15.2.54"
_cell_length_a                 7.87000
_cell_length_b                 7.87000
_cell_length_c                 12.14000
_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 -y+3/4,x+1/4,z+1/2,+1 
3 y+3/4,-x+3/4,z+1/2,+1 
4 y+3/4,x+1/4,-z+1/2,+1 
5 -y+3/4,-x+3/4,-z+1/2,+1 
6 -x+1/2,-y,z,+1 
7 -x+1/2,y,-z,+1 
8 x,-y,-z,+1 
9 -x+1/2,-y+1/2,-z,+1 
10 y+1/4,-x+3/4,-z+1/2,+1 
11 -y+1/4,x+1/4,-z+1/2,+1 
12 -y+1/4,-x+3/4,z+1/2,+1 
13 y+1/4,x+1/4,z+1/2,+1 
14 x,y+1/2,-z,+1 
15 x,-y+1/2,z,+1 
16 -x+1/2,y+1/2,z,+1 

loop_
_space_group_symop_magn_centering.id
_space_group_symop_magn_centering.xyz
1 x,y,z,+1 
2 x+1/2,y+1/2,z,+1 
3 x,y+1/2,z,-1 
4 x+1/2,y,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
Nd1 Nd 0.00000 0.00000 0.35160 1
Cu1 Cu 0.00000 0.00000 0.00000 1
O1_1 O 0.00000 0.25000 0.00000 1
O1_2 O 0.25000 0.00000 0.00000 1
O2_1 O 0.00000 0.25000 0.25000 1
O2_2 O 0.25000 0.00000 0.25000 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
_atom_site_moment.magnitude
_atom_site_moment.spherical_azimuthal
_atom_site_moment.spherical_polar
Nd1 0.0 0.0 0.0 mx,0,0 0.0 ? ?
Cu1 0.4 0.0 0.0 mx,0,0 0.4 ? ?

