Potassium sodium (2<i>R</i>,3<i>R</i>)-tartrate tetrahydrate: the paraelectric phase of Rochelle salt at 105 K
Görbitz, Carl Henrik; Sagstuen, Einar; Acta Crystallographica Section E 64 (2008) m507–m508; doi:10.1107/S1600536808005266

data_2217854
_publ_section_title
;
 Potassium sodium (2<i>R</i>,3<i>R</i>)-tartrate tetrahydrate: the
 paraelectric phase of Rochelle salt at 105 K
;
_journal_coeditor_code           BG2163
_journal_issue                   4
_journal_name_full               'Acta Crystallographica Section E'
_journal_page_first              m507
_journal_page_last               m508
_journal_paper_doi               10.1107/S1600536808005266
_journal_volume                  64
_journal_year                    2008
_chemical_formula_iupac          'K +, Na +, C4 H4 O6 2-, 4 H2 O'
_chemical_formula_moiety         'K +, Na +, C4 H4 O6 2-, 4(H2 O)'
_chemical_formula_sum            'C4 H12 K Na O10'
_chemical_formula_weight         282.23
_chemical_name_common            'Rochelle salt'
_chemical_name_systematic
;
Potassium sodium (2R,3R)-tartrate tetrahydrate
;
_space_group_IT_number           18
_space_group_name_Hall           'P 2 2ab'
_symmetry_cell_setting           orthorhombic
_symmetry_space_group_name_Hall  'P 2 2ab'
_symmetry_space_group_name_H-M   'P 21 21 2'
_atom_sites_solution_hydrogens   difmap
_atom_sites_solution_primary     direct
_audit_creation_method           SHELXL-97
_cell_angle_alpha                90.00
_cell_angle_beta                 90.00
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   11.7859(6)
_cell_length_b                   14.1972(7)
_cell_length_c                   6.1875(3)
_cell_measurement_reflns_used    10000
_cell_measurement_temperature    105(2)
_cell_measurement_theta_max      49.65
_cell_measurement_theta_min      2.87
_cell_volume                     1035.33(9)
_computing_cell_refinement       'SAINT-Plus (Bruker, 2001)'
_computing_data_collection       'SMART (Bruker, 1998)'
_computing_data_reduction        'SAINT-Plus (Bruker, 2001)'
_computing_molecular_graphics    'SHELXTL (Sheldrick, 2008)'
_computing_publication_material  'SHELXTL (Sheldrick, 2008)'
_computing_structure_refinement  'SHELXTL (Sheldrick, 2008)'
_computing_structure_solution    'SHELXTL (Sheldrick, 2008)'
_diffrn_ambient_temperature      105(2)
_diffrn_detector_area_resol_mean 8.3
_diffrn_measured_fraction_theta_full 0.980
_diffrn_measured_fraction_theta_max 0.972
_diffrn_measurement_device_type  'Siemens SMART CCD'
_diffrn_measurement_method
'sets of exposures each taken over 0.3\% \w rotation'
_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  0.0373
_diffrn_reflns_av_sigmaI/netI    0.0386
_diffrn_reflns_limit_h_max       25
_diffrn_reflns_limit_h_min       -25
_diffrn_reflns_limit_k_max       30
_diffrn_reflns_limit_k_min       -28
_diffrn_reflns_limit_l_max       12
_diffrn_reflns_limit_l_min       -12
_diffrn_reflns_number            33523
_diffrn_reflns_theta_full        49.12
_diffrn_reflns_theta_max         49.65
_diffrn_reflns_theta_min         2.87
_diffrn_standards_decay_%        0
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    0.597
_exptl_absorpt_correction_T_max  0.5506
_exptl_absorpt_correction_T_min  0.3977
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   '(SADABS; Sheldrick, 1996)'
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.811
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       sphere
_exptl_crystal_F_000             584
_exptl_crystal_size_rad          0.5
_refine_diff_density_max         0.498
_refine_diff_density_min         -0.731
_refine_ls_abs_structure_details 'Flack, 1983, 4266 Friedel pairs'
_refine_ls_abs_structure_Flack   0.044(14)
_refine_ls_extinction_coef       0.132(3)
_refine_ls_extinction_expression Fc^*^=kFc[1+0.001xFc^2^\l^3^/sin(2\q)]^-1/4^
_refine_ls_extinction_method     'SHELXTL (Bruker, 2000)'
_refine_ls_goodness_of_fit_ref   1.063
_refine_ls_hydrogen_treatment    refall
_refine_ls_matrix_type           full
_refine_ls_number_parameters     195
_refine_ls_number_reflns         10040
_refine_ls_number_restraints     12
_refine_ls_restrained_S_all      1.064
_refine_ls_R_factor_all          0.0355
_refine_ls_R_factor_gt           0.0292
_refine_ls_shift/su_max          0.002
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0324P)^2^+0.0088P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0668
_refine_ls_wR_factor_ref         0.0688
_reflns_number_gt                8947
_reflns_number_total             10040
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            bg2163.cif
_cod_data_source_block           I
_cod_database_code               2217854
_cod_database_fobs_code          2217854