Electron density distribution and Madelung potential in α-spodumene, LiAl(SiO~3~)~2~, from two-wavelength high-resolution X-ray diffraction data
Kuntzinger, Sandrine; Ghermani, Nour Eddine; Acta Crystallographica Section B 55 (1999) 273–284; doi:10.1107/S0108768198013536

data_2003130
_publ_section_title
;
 Electron density distribution and Madelung potential in \a-spodumene,
 LiAl(SiO~3~)~2~, from two-wavelength high-resolution X-ray diffraction
 data
;
_journal_issue                   3
_journal_name_full               'Acta Crystallographica Section B'
_journal_page_first              273
_journal_page_last               284
_journal_paper_doi               10.1107/S0108768198013536
_journal_volume                  55
_journal_year                    1999
_chemical_formula_iupac          'Li Al (Si O3)2'
_chemical_formula_sum            'Al Li O6 Si2'
_chemical_formula_weight         186.09
_space_group_IT_number           15
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  '-C 2yc'
_symmetry_space_group_name_H-M   'C 1 2/c 1'
_cell_angle_alpha                90.00
_cell_angle_beta                 110.130(10)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   9.4560(10)
_cell_length_b                   8.3860(10)
_cell_length_c                   5.2160(10)
_cell_measurement_reflns_used    25
_cell_measurement_temperature    293
_cell_measurement_theta_max      23.6
_cell_measurement_theta_min      9.4
_cell_volume                     388.35(10)
_computing_cell_refinement       'CAD-4 (Enraf-Nonius, 1989)'
_computing_data_collection       'CAD-4 (Enraf-Nonius, 1989)'
_computing_data_reduction        'DREADD (Blessing, 1987, 1989)'
_computing_structure_refinement  'MOLLY (Hansen & Coppens, 1978)'
_diffrn_measured_fraction_theta_full .93
_diffrn_measured_fraction_theta_max .93
_diffrn_measurement_device       'Enraf-Nonius CAD4 diffractometer'
_diffrn_measurement_method       '\w/2\q scans'
_diffrn_radiation_type           'Ag K\a'
_diffrn_radiation_wavelength     0.5608
_diffrn_reflns_av_R_equivalents  0.0210
_diffrn_reflns_limit_h_max       23
_diffrn_reflns_limit_h_min       -23
_diffrn_reflns_limit_k_max       21
_diffrn_reflns_limit_k_min       -21
_diffrn_reflns_limit_l_max       13
_diffrn_reflns_limit_l_min       -13
_diffrn_reflns_number            15850
_diffrn_reflns_theta_full        45.0
_diffrn_reflns_theta_max         45.0
_diffrn_reflns_theta_min         2.6
_diffrn_standards_decay_%        0
_diffrn_standards_interval_time  120
_diffrn_standards_number         4
_exptl_absorpt_coefficient_mu    .54
_exptl_absorpt_correction_T_max  .97
_exptl_absorpt_correction_T_min  .82
_exptl_crystal_colour            Colourless
_exptl_crystal_density_diffrn    3.18
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       Parallelepiped
_exptl_crystal_F_000             368.0
_exptl_crystal_size_max          .36
_exptl_crystal_size_mid          .18
_exptl_crystal_size_min          .06
_refine_diff_density_max         0.2
_refine_diff_density_min         -0.1
_refine_ls_extinction_coef       4.9.10^2^
_refine_ls_goodness_of_fit_ref   .84
_refine_ls_number_parameters     138
_refine_ls_number_reflns         2261
_refine_ls_R_factor_gt           .0155
_refine_ls_shift/su_max          0.0
_refine_ls_structure_factor_coef F
_refine_ls_weighting_details     w=1/[\s^2^(F^2^)+(0.0160F^2^)^2^]
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_ref         .0151
_reflns_number_gt                2261
_reflns_number_total             3241
_reflns_threshold_expression     I>3\s(I)
_cod_data_source_file            sh0121.cif
_cod_data_source_block           II
_cod_original_cell_volume        388.36(9)
_cod_database_code               2003130
_cod_database_fobs_code          2003130