Ln3T2N6 (Ln=La, Ce, Pr; T=Ta, Nb), a New Family of Ternary Nitrides Isotypic to a High Tc Cuprate Superconductor
Cario, L.; Gal, Z. A.; Braun, T. P.; DiSalvo, F. J.; Blaschkowski, B.; Meyer, H. J.; Journal of Solid State Chemistry 162 (2001) 90–95; doi:10.1006/jssc.2001.9359

data_1004014
_publ_section_title
;
Ln3T2N6 (Ln=La, Ce, Pr; T=Ta, Nb), a New Family of Ternary Nitrides Isotypic 
to a High Tc Cuprate Superconductor
;
_journal_name_full               'Journal of Solid State Chemistry'
_journal_page_first              90
_journal_page_last               95
_journal_paper_doi               10.1006/jssc.2001.9359
_journal_volume                  162
_journal_year                    2001
_chemical_formula_moiety         ?
_chemical_formula_sum            'La3 N6 Ta1.8'
_chemical_formula_weight         826.50
_chemical_melting_point          ?
_chemical_name_common            'Lanthanum three tantalum two hexanitride'
_chemical_name_systematic        ?
_space_group_IT_number           139
_symmetry_cell_setting           tetragonal
_symmetry_space_group_name_Hall  '-I 4 2'
_symmetry_space_group_name_H-M   'I 4/m m m'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_cell_angle_alpha                90.00
_cell_angle_beta                 90.00
_cell_angle_gamma                90.00
_cell_formula_units_Z            2
_cell_length_a                   4.0399(6)
_cell_length_b                   4.0399(6)
_cell_length_c                   20.185(4)
_cell_measurement_reflns_used    439
_cell_measurement_temperature    155(5)
_cell_measurement_theta_max      27.87
_cell_measurement_theta_min      2.02
_cell_volume                     329.44(10)
_computing_cell_refinement       'Brucker Smart 5.050'
_computing_data_collection       'Brucker Smart 5.050'
_computing_data_reduction        'SHELXL-97 (Sheldrick, 1997)'
_computing_molecular_graphics    ?
_computing_publication_material  ?
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    ?
_diffrn_ambient_temperature      293(2)
_diffrn_detector_area_resol_mean ?
_diffrn_measured_fraction_theta_full 0.948
_diffrn_measured_fraction_theta_max 0.948
_diffrn_measurement_device_type  'Bruker Smart CCD'
_diffrn_measurement_method       w-scan
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0601
_diffrn_reflns_av_sigmaI/netI    0.0288
_diffrn_reflns_limit_h_max       5
_diffrn_reflns_limit_h_min       -2
_diffrn_reflns_limit_k_max       5
_diffrn_reflns_limit_k_min       -4
_diffrn_reflns_limit_l_max       25
_diffrn_reflns_limit_l_min       -23
_diffrn_reflns_number            873
_diffrn_reflns_theta_full        27.87
_diffrn_reflns_theta_max         27.87
_diffrn_reflns_theta_min         2.02
_diffrn_standards_decay_%        ?
_diffrn_standards_interval_count ?
_diffrn_standards_interval_time  ?
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    48.736
_exptl_absorpt_correction_T_max  0.44372
_exptl_absorpt_correction_T_min  0.13355
_exptl_absorpt_correction_type   analytical
_exptl_absorpt_process_details   'Gaussian face-indexed absorption correction'
_exptl_crystal_colour            Black
_exptl_crystal_density_diffrn    8.332
_exptl_crystal_density_meas      ?
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       'truncated parallelepiped'
_exptl_crystal_F_000             689
_exptl_crystal_size_max          0.076
_exptl_crystal_size_mid          0.042
_exptl_crystal_size_min          0.017
_refine_diff_density_max         1.552
_refine_diff_density_min         -2.893
_refine_diff_density_rms         0.482
_refine_ls_extinction_coef       0.0017(3)
_refine_ls_extinction_expression Fc^*^=kFc[1+0.001xFc^2^\l^3^/sin(2\q)]^-1/4^
_refine_ls_extinction_method     SHELXL
_refine_ls_goodness_of_fit_ref   1.189
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     15
_refine_ls_number_reflns         147
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.189
_refine_ls_R_factor_all          0.0341
_refine_ls_R_factor_gt           0.0243
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0000P)^2^+54.5734P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0506
_refine_ls_wR_factor_ref         0.0671
_reflns_number_gt                130
_reflns_number_total             147
_reflns_threshold_expression     >2sigma(I)
_cod_depositor_comments
;
The following automatic conversions were performed:
'_symmetry_cell_setting' value 'Tetragonal' changed to 'tetragonal'
according to '/home/saulius/struct/CIF-dictionaries/cif_core.dic'
dictionary named 'cif_core.dic' version 2.4.1 from
2010-06-29.

'_exptl_absorpt_correction_type' value 'Analytical' changed
to 'analytical' according to
'/home/saulius/struct/CIF-dictionaries/cif_core.dic' dictionary named
'cif_core.dic' version 2.4.1 from 2010-06-29.

Automatic conversion script
Id: cif_fix_enum 1527 2010-12-29 10:47:43Z saulius 

Fixing incorrect cif tag. _atom_site_type_symbol symbol was changed to 
_atom_site_Wyckoff_symbol. For the correct values, the
original paper at
http://www.sciencedirect.com/science/article/pii/S0022459601993594# was
consulted.

Antanas Vaitkus
2013-03-08

Correcting syntax of Wyckoff letters. However, the Wyckoff letter for
the N2 atom might be incorrect (as judged from the N2 coordinates); bu
the original paper specifies 4e as the Wyckoff position for N2...

Saulius Gra\<zulis
2013-03-29
;
_cod_original_sg_symbol_H-M      I4/mmm
_cod_original_formula_sum        'La3 N6 Ta1.80'
_cod_database_code               1004014