Evolution of the α-BaMg(CO<sub>3</sub>)<sub>2</sub> low-temperature superstructure and the tricritical nature of its α-β phase transition.
Ende, Martin; Effenberger, Herta; Miletich, Ronald; Acta crystallographica Section B, Structural science, crystal engineering and materials 73 (2017) 827–835; doi:10.1107/S2052520617009295

data_2311744
_publ_section_title
;
 Evolution of the \a-BaMg(CO<sub>3</sub>)<sub>2</sub> low-temperature
 superstructure and the tricritical nature of its \a-\b phase transition.
;
_journal_issue                   'Pt 5'
_journal_name_full
'Acta crystallographica Section B, Structural science, crystal engineering and materials'
_journal_page_first              827
_journal_page_last               835
_journal_paper_doi               10.1107/S2052520617009295
_journal_volume                  73
_journal_year                    2017
_chemical_formula_sum            'C6 Ba3 Mg3 O18'
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_computing_structure_refinement  'SHELXL-2014/7 (Sheldrick, 2014)'
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_diffrn_measured_fraction_theta_max 0.996
_diffrn_measurement_device_type  StoeStadiVari
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0304
_diffrn_reflns_av_unetI/netI     0.0140
_diffrn_reflns_Laue_measured_fraction_full 0.993
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_diffrn_reflns_limit_h_max       9
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_diffrn_reflns_limit_k_min       -9
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_diffrn_reflns_point_group_measured_fraction_full 0.993
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_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         45.574
_diffrn_reflns_theta_min         3.647
_exptl_absorpt_coefficient_mu    8.259
_exptl_absorpt_correction_T_max  0.8
_exptl_absorpt_correction_T_min  0.7
_exptl_absorpt_correction_type   numerical
_exptl_absorpt_process_details   '(Stoe & Cie GmbH 2016)'
_exptl_crystal_density_diffrn    3.850
_exptl_crystal_description       prismatic
_exptl_crystal_F_000             768
_exptl_crystal_size_max          0.060
_exptl_crystal_size_mid          0.030
_exptl_crystal_size_min          0.030
_refine_diff_density_max         0.543
_refine_diff_density_min         -0.584
_refine_diff_density_rms         0.122
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   0.954
_refine_ls_hydrogen_treatment    undef
_refine_ls_matrix_type           full
_refine_ls_number_parameters     17
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_refine_ls_restrained_S_all      0.954
_refine_ls_R_factor_all          0.0199
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_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.0117P)^2^] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
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_refine_ls_wR_factor_ref         0.0204
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_reflns_number_gt                515
_reflns_number_total             697
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            xk5041sup1.cif
_cod_data_source_block           norse_200
_cod_original_cell_volume        728.92(4)
_cod_original_sg_symbol_H-M      'R -3 c'
_cod_database_code               2311744
_shelx_shelxl_version_number     2014/7
_shelx_estimated_absorpt_t_min   0.637
_shelx_estimated_absorpt_t_max   0.790
_shelx_res_checksum              84915
_shelx_hkl_checksum              97074