Two ammonium tetrachloridoaluminate salts: how a twinned orthorhombic structure emulates a trigonal crystal system
Tillmann, Jan; Lerner, Hans-Wolfram; Bolte, Michael; Acta Crystallographica Section C Structural Chemistry 70 (2014) –; doi:10.1107/S2053229614022621

data_2019729
_publ_section_title
;
 Two ammonium tetrachloridoaluminate salts: how a twinned orthorhombic
 structure emulates a trigonal crystal system
;
_journal_coeditor_code           SK3567
_journal_issue                   12
_journal_name_full
'Acta Crystallographica Section C Structural Chemistry'
_journal_paper_doi               10.1107/S2053229614022621
_journal_volume                  70
_journal_year                    2014
_chemical_formula_iupac          '(C8 H20 N) [Al Cl4]'
_chemical_formula_moiety         'C8 H20 N +, Al Cl4 -'
_chemical_formula_sum            'C8 H20 Al Cl4 N'
_chemical_formula_weight         299.03
_chemical_name_systematic
;
Tetraethylammonium tetrachloridoaluminate
;
_space_group_crystal_system      orthorhombic
_space_group_IT_number           29
_space_group_name_Hall           'P 2c -2ac'
_space_group_name_H-M_alt        'P c a 21'
_symmetry_space_group_name_Hall  'P 2c -2ac'
_symmetry_space_group_name_H-M   'P c a 21'
_atom_sites_solution_hydrogens   geom
_audit_creation_method           SHELXL-2014
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   14.0348(10)
_cell_length_b                   8.1362(7)
_cell_length_c                   12.8892(12)
_cell_measurement_reflns_used    13398
_cell_measurement_temperature    173(2)
_cell_measurement_theta_max      26.43
_cell_measurement_theta_min      3.21
_cell_volume                     1471.8(2)
_computing_cell_refinement
;
X-AREA (Stoe & Cie, 2001)
;
_computing_data_collection
;
X-AREA (Stoe & Cie, 2001)
;
_computing_data_reduction
;
X-AREA (Stoe & Cie, 2001)
;
_computing_molecular_graphics
;
XP in SHELXTL (Sheldrick, 2008) and Mercury (Macrae <i>et al.</i>, 2008)
;
_computing_publication_material
;
publCIF (Westrip, 2010), SHELXL97 (Sheldrick, 2008) and PLATON
(Spek, 2009)
;
_computing_structure_refinement
;
SHELXL97 (Sheldrick, 2008)
;
_computing_structure_solution
;
SHELXS97(Sheldrick, 2008)
;
_diffrn_ambient_temperature      173(2)
_diffrn_measured_fraction_theta_full 0.953
_diffrn_measured_fraction_theta_max 0.950
_diffrn_measurement_device_type  'Stoe IPDS II two-circle-diffractometer'
_diffrn_measurement_method       \w
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.028
_diffrn_reflns_limit_h_max       15
_diffrn_reflns_limit_h_min       0
_diffrn_reflns_limit_k_max       9
_diffrn_reflns_limit_k_min       -4
_diffrn_reflns_limit_l_max       15
_diffrn_reflns_limit_l_min       -15
_diffrn_reflns_number            6472
_diffrn_reflns_theta_full        25.000
_diffrn_reflns_theta_max         25.843
_diffrn_reflns_theta_min         4.034
_exptl_absorpt_coefficient_mu    0.833
_exptl_absorpt_correction_T_max  0.904
_exptl_absorpt_correction_T_min  0.897
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
X-AREA (Stoe & Cie, 2001)
;
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.349
_exptl_crystal_description       block
_exptl_crystal_F_000             624
_exptl_crystal_size_max          0.100
_exptl_crystal_size_mid          0.100
_exptl_crystal_size_min          0.100
_refine_diff_density_max         0.201
_refine_diff_density_min         -0.146
_refine_ls_abs_structure_details
;
Flack x determined using 1046 quotients [(I+)-(I-)]/[(I+)+(I-)]
(Parsons <i>et al.</i>, 2013)
;
_refine_ls_abs_structure_Flack   -0.04(5)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.103
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     129
_refine_ls_number_reflns         2522
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      1.103
_refine_ls_R_factor_all          0.0245
_refine_ls_R_factor_gt           0.0226
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.0263P)^2^] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0514
_refine_ls_wR_factor_ref         0.0518
_reflns_number_gt                2423
_reflns_number_total             2522
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            sk3567sup1.cif
_cod_data_source_block           II
_cod_database_code               2019729
_cod_database_fobs_code          2019729
_shelx_estimated_absorpt_t_min   0.921
_shelx_estimated_absorpt_t_max   0.921
_shelx_hkl_checksum              36290
_shelx_res_checksum              15379
_shelxl_version_number           2014/6