Modulated crystal structure of incommensurate low tridymite
Graetsch, Heribert A.; Acta Crystallographica Section B 65 (2009) 543–550; doi:10.1107/S0108768109029127

data_2104422
_publ_section_title
;
 Modulated crystal structure of incommensurate low tridymite
;
_journal_coeditor_code           CK5037
_journal_issue                   5
_journal_name_full               'Acta Crystallographica Section B'
_journal_page_first              543
_journal_page_last               550
_journal_paper_doi               10.1107/S0108768109029127
_journal_volume                  65
_journal_year                    2009
_chemical_formula_sum            'O2 Si'
_chemical_formula_weight         60.1
_chemical_name_common            tridymite
_chemical_name_systematic        ' ?'
_space_group_ssg_name            Cc(\a0\g)0
_symmetry_cell_setting           monoclinic
_cell_angle_alpha                90
_cell_angle_beta                 91.57(2)
_cell_angle_gamma                90
_cell_formula_units_Z            8
_cell_length_a                   5.007(2)
_cell_length_b                   8.599(2)
_cell_length_c                   8.2202(16)
_cell_measurement_temperature    294
_cell_modulation_dimension       1
_cell_volume                     353.79(18)
_computing_publication_material
'Jana2006 (Petricek, Dusek & Palatinus, 2006)'
_computing_structure_refinement
'Jana2006 (Petricek, Dusek & Palatinus, 2006)'
_diffrn_ambient_temperature      293
_diffrn_measured_fraction_theta_full 0.98
_diffrn_measurement_device       'four-cycle diffractometer'
_diffrn_measurement_device_type  'Oxford Diffraction CCD'
_diffrn_measurement_method       '2phi and 4omega scans'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'X-ray tube'
_diffrn_radiation_type           'Mo K\a'
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0402
_diffrn_reflns_av_sigmaI/netI    0.0774
_diffrn_reflns_limit_h_max       7
_diffrn_reflns_limit_h_min       -7
_diffrn_reflns_limit_index_m_1_max 3
_diffrn_reflns_limit_index_m_1_min -3
_diffrn_reflns_limit_k_max       16
_diffrn_reflns_limit_k_min       -15
_diffrn_reflns_limit_l_max       15
_diffrn_reflns_limit_l_min       -12
_diffrn_reflns_number            23130
_diffrn_reflns_theta_full        31.09
_diffrn_reflns_theta_max         41.95
_diffrn_reflns_theta_min         2.68
_exptl_absorpt_coefficient_mu    0.846
_exptl_absorpt_correction_T_max  1
_exptl_absorpt_correction_T_min  1
_exptl_absorpt_correction_type   none
_exptl_crystal_density_diffrn    2.255
_exptl_crystal_density_meas      ?
_exptl_crystal_density_method    .
_exptl_crystal_F_000             240
_refine_diff_density_max         0.36
_refine_diff_density_min         -0.34
_refine_ls_extinction_coef       464E1(9)
_refine_ls_extinction_method
'B-C type 1 Gaussian isotropic (Becker & Coppens, 1974)'
_refine_ls_goodness_of_fit_ref   0.99
_refine_ls_number_constraints    0
_refine_ls_number_parameters     293
_refine_ls_number_reflns         7927
_refine_ls_number_restraints     20
_refine_ls_R_factor_all          0.0755
_refine_ls_R_factor_gt           0.0303
_refine_ls_shift/su_max          0.0078
_refine_ls_shift/su_mean         0.0013
_refine_ls_structure_factor_coef F
_refine_ls_weighting_details     w=1/(\s^2^(F)+0.0001F^2^)
_refine_ls_weighting_scheme      sigma
_refine_ls_wR_factor_gt          0.0295
_refine_ls_wR_factor_ref         0.0359
_reflns_number_gt                3679
_reflns_number_total             7927
_reflns_threshold_expression     I>3\s(I)
_cod_data_source_file            ck5037.cif
_cod_data_source_block           I
_cod_depositor_comments
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The following automatic conversions were performed:
'_exptl_absorpt_correction_type' value 'None' changed to 'none' according
to '/home/saulius/struct/CIF-dictionaries/cif_core.dic' dictionary named
'cif_core.dic' version 2.4.1 from 2010-06-29.

Automatic conversion script
Id: cif_fix_enum 1527 2010-12-29 10:47:43Z saulius 

The following automatic conversions were performed:

'_exptl_absorpt_correction_type' value 'None' changed to 'none'
according to /home/saulius/struct/CIF-dictionaries/cif_core.dic
dictionary named 'cif_core.dic' version 2.4.1 from 2010-06-29.

Automatic conversion script
Id: cif_fix_values 1715 2011-07-08 13:25:40Z adriana 
;
_cod_original_formula_sum        'O2 Si1'
_cod_database_code               2104422
_cod_database_fobs_code          2104422