Rietveld structure analysis of keatite, a rare, metastable SiO2 polymorph
Grosskreuz, Isabel; Marler, Bernd; Zeitschrift für Kristallographie - New Crystal Structures 238 (2023) 655–657; doi:10.1515/ncrs-2023-0135

data_8107522
_publ_section_title
;
 Rietveld structure analysis of keatite, a rare, metastable SiO2 polymorph
;
_journal_issue                   4
_journal_name_full
'Zeitschrift f\"ur Kristallographie - New Crystal Structures'
_journal_page_first              655
_journal_page_last               657
_journal_paper_doi               10.1515/ncrs-2023-0135
_journal_volume                  238
_journal_year                    2023
_chemical_formula_moiety         'O6 Si3'
_chemical_formula_structural     (Si3O6)4
_chemical_formula_sum            'O6 Si3'
_chemical_formula_weight         180.26
_chemical_name_common            keatite
_space_group_IT_number           96
_space_group_name_Hall           'P 4nw 2abw'
_space_group_name_H-M_alt        'P 43 21 2'
_symmetry_cell_setting           tetragonal
_symmetry_space_group_name_Hall  'P 4nw 2abw'
_symmetry_space_group_name_H-M   'P 43 21 2'
_cell_angle_alpha                90.0000
_cell_angle_beta                 90.0000
_cell_angle_gamma                90.0000
_cell_formula_units_Z            4
_cell_length_a                   7.4462(1)
_cell_length_b                   7.4462(1)
_cell_length_c                   8.5838(4)
_cell_measurement_temperature    293
_cell_volume                     475.94(2)
_computing_structure_refinement  FULLPROF
_diffrn_ambient_temperature      293
_diffrn_detector                 BRAUN
_diffrn_detector_area_resol_mean 6?theta
_diffrn_detector_type            'Position sensitive detector'
_diffrn_measurement_device_type  'Siemens D5000'
_diffrn_measurement_method       'Debye-Scherrer Geometry'
_diffrn_radiation_monochromator  'Ge (111)'
_diffrn_radiation_type           'Cu K\a'
_diffrn_source                   'X-ray tube'
_diffrn_source_target            Cu
_exptl_crystal_density_diffrn    2.50
_pd_char_colour                  'light yellow'
_pd_char_particle_morphology     flat_sheet
_pd_instr_location               ' ?'
_pd_meas_2theta_range_inc        0.007863
_pd_meas_2theta_range_max        93.60570
_pd_meas_2theta_range_min        14.04720
_pd_meas_number_of_points        10121
_pd_meas_scan_method             cont
_pd_proc_2theta_range_inc        0.007863
_pd_proc_2theta_range_max        93.6740
_pd_proc_2theta_range_min        14.1155
_pd_proc_ls_background_function  'Linear interpolation between bgrd. points'
_pd_proc_ls_pref_orient_corr     none
_pd_proc_ls_profile_function     'Thompson-Cox-Hastings pseudo-Voigt function'
_pd_proc_ls_prof_R_factor        3.0904
_pd_proc_ls_prof_wR_expected     2.2218
_pd_proc_ls_prof_wR_factor       4.0553
_pd_proc_wavelength              1.540590
_pd_spec_mounting                ' ?'
_pd_spec_mount_mode              transmission
_pd_spec_shape                   cylinder
_refine_ls_goodness_of_fit_all   1.8253
_refine_ls_number_parameters     16
_refine_ls_number_reflns         185
_refine_ls_number_restraints     19
_refine_ls_R_I_factor            3.3340
_cod_data_source_file            suppl_j_ncrs-2023-0135_suppl_001.cif
_cod_data_source_block           keatit
_cod_depositor_comments
;
The following automatic conversions were performed:

data item '_symmetry_cell_setting' value 'Tetragonal' was changed to
'tetragonal' in accordance with the built-in table derived from the
CIF Core dictionary named 'cif_core.dic' version 2.4.5 last updated
on 2014-11-21.

Automatic conversion script
Id: cif_fix_values 8738 2021-04-28 16:35:53Z antanas 
;
_cod_original_cell_volume        475.93(3)
_cod_database_code               8107522
_pd_proc_ls_prof_cr_factor       9.8920
_pd_proc_ls_prof_cwr_factor      9.4258
_pd_proc_ls_prof_cwr_expected    5.1641
_pd_proc_ls_prof_chi2            3.3316
_pd_proc_ls_prof_echi2           3.3316