Bis(2-methyl-2-propanammonium) chromate
Chebbi, Hammouda; Driss, Ahmed; Acta Crystallographica Section E 58 (2002) m494–m496; doi:10.1107/S1600536802012412

data_2201477
_publ_section_title
;
 Bis(2-methyl-2-propanammonium) chromate
;
_journal_issue                   9
_journal_name_full               'Acta Crystallographica Section E'
_journal_page_first              m494
_journal_page_last               m496
_journal_paper_doi               10.1107/S1600536802012412
_journal_volume                  58
_journal_year                    2002
_chemical_formula_iupac          '(C4 H12 N)2 [Cr1 O4]'
_chemical_formula_moiety         'C8 H24 Cr N2 O4'
_chemical_formula_structural     '(C4 H12 N)2 [Cr1 O4]'
_chemical_formula_sum            'C8 H24 Cr N2 O4'
_chemical_formula_weight         264.29
_chemical_name_systematic
;
Bis(2-methyl-2-propanammonium) chromate
;
_space_group_IT_number           167
_symmetry_cell_setting           trigonal
_symmetry_space_group_name_Hall  '-R 3 2"c'
_symmetry_space_group_name_H-M   'R -3 c :H'
_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                120.00
_cell_formula_units_Z            6
_cell_length_a                   6.7200(10)
_cell_length_b                   6.7200(10)
_cell_length_c                   54.330(9)
_cell_measurement_reflns_used    15
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      14
_cell_measurement_theta_min      11
_cell_volume                     2124.8(6)
_computing_cell_refinement       'CAD-4 EXPRESS'
_computing_data_collection
'CAD-4 EXPRESS (Duisenberg, 1992; Mac\'i\<cek & Yordanov, 1992)'
_computing_data_reduction        'MolEN (Fair, 1990)'
_computing_molecular_graphics    'PLATON (Spek, 1998)'
_computing_publication_material  SHELXL97
_computing_structure_refinement  'SHELXL97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS97 (Sheldrick, 1997)'
_diffrn_ambient_temperature      293(2)
_diffrn_measured_fraction_theta_full 0.998
_diffrn_measured_fraction_theta_max 0.998
_diffrn_measurement_device_type  'Enraf-Nonius CAD-4'
_diffrn_measurement_method       \w/2\q
_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  0.0572
_diffrn_reflns_av_sigmaI/netI    0.0388
_diffrn_reflns_limit_h_max       8
_diffrn_reflns_limit_h_min       0
_diffrn_reflns_limit_k_max       0
_diffrn_reflns_limit_k_min       -8
_diffrn_reflns_limit_l_max       69
_diffrn_reflns_limit_l_min       -69
_diffrn_reflns_number            1936
_diffrn_reflns_theta_full        26.95
_diffrn_reflns_theta_max         26.95
_diffrn_reflns_theta_min         3.58
_diffrn_standards_decay_%        0.4
_diffrn_standards_interval_time  120
_diffrn_standards_number         2
_exptl_absorpt_coefficient_mu    0.807
_exptl_absorpt_correction_T_max  0.893
_exptl_absorpt_correction_T_min  0.802
_exptl_absorpt_correction_type   '\y scan'
_exptl_absorpt_process_details   '(North et al., 1968)'
_exptl_crystal_colour            yellow
_exptl_crystal_density_diffrn    1.239
_exptl_crystal_density_meas      ?
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       'hexagonal prism'
_exptl_crystal_F_000             852
_exptl_crystal_size_max          0.28
_exptl_crystal_size_mid          0.25
_exptl_crystal_size_min          0.14
_refine_diff_density_max         0.173
_refine_diff_density_min         -0.155
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.371
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     35
_refine_ls_number_reflns         524
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.371
_refine_ls_R_factor_all          0.0650
_refine_ls_R_factor_gt           0.0363
_refine_ls_shift/su_max          <0.001
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w = 1/[\s^2^(Fo^2^)+(0.020P)^2^+0.149P] where P = (Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0837
_refine_ls_wR_factor_ref         0.0905
_reflns_number_gt                359
_reflns_number_total             524
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            dn6036.cif
_cod_data_source_block           I
_cod_depositor_comments
;
The following automatic conversions were performed:

'_exptl_crystal_density_meas' value 'not measured' was changed to '?'
- the value is perceived as not measured.

Automatic conversion script
Id: cif_fix_values 3008 2015-01-20 13:52:24Z robertas 
;
_cod_original_sg_symbol_H-M      'R -3 c'
_cod_database_code               2201477
_cod_database_fobs_code          2201477