Reinvestigation of the crystal structure of Ca~2~Ce~8~(SiO~4~)~6~O~2~ apatite by Rietveld refinement
Massoni, Nicolas; Hegron, Ronan; Campayo, Lionel; Acta Crystallographica Section E 74 (2018) 955–959; doi:10.1107/S2056989018008435

data_2242532
_publ_section_title
;
 Reinvestigation of the crystal structure of Ca~2~Ce~8~(SiO~4~)~6~O~2~
 apatite by Rietveld refinement
;
_journal_issue                   7
_journal_name_full               'Acta Crystallographica Section E'
_journal_page_first              955
_journal_page_last               959
_journal_paper_doi               10.1107/S2056989018008435
_journal_volume                  74
_journal_year                    2018
_chemical_formula_iupac          'Ca2 Ce8 (Si O4)6 O2'
_chemical_formula_structural     'Ca2 Ce8 O26 Si6'
_chemical_formula_sum            'Ca2 Ce8 O26 Si6'
_chemical_formula_weight         1785.6
_chemical_name_systematic
;
Dicalcium octacerium hexakis(silicate) dioxide
;
_space_group_crystal_system      hexagonal
_space_group_IT_number           176
_space_group_name_Hall           '-P 6c'
_space_group_name_H-M_alt        'P 63/m'
_symmetry_space_group_name_Hall  '-P 6c'
_symmetry_space_group_name_H-M   'P 63/m'
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                120
_cell_formula_units_Z            1
_cell_length_a                   9.59912(6)
_cell_length_b                   9.59912(6)
_cell_length_c                   7.09284(6)
_cell_measurement_reflns_used    353
_cell_measurement_temperature    293
_cell_measurement_theta_max      65.005
_cell_measurement_theta_min      5.0115
_cell_volume                     565.996(7)
_computing_cell_refinement
;
<i>JANA2006</i> (Pet\<r\'i\<cek <i>et al.</i>,  2014)
;
_computing_data_collection
;
<i>Data Collector</i> (Panalytical, 2011)
;
_computing_data_reduction
;
<i>JANA2006</i> (Pet\<r\'i\<cek <i>et al.</i>,  2014)
;
_computing_molecular_graphics
;
<i>VESTA</i> (Momma & Izumi, 2011)
;
_computing_publication_material
;
publCIF (Westrip, 2010)
;
_computing_structure_refinement
;
<i>JANA2006</i> (Pet\<r\'i\<cek <i>et al.</i>,  2014)
;
_computing_structure_solution
;
<i>JANA2006</i> (Pet\<r\'i\<cek <i>et al.</i>,  2014)
;
_diffrn_ambient_temperature      293
_diffrn_measurement_device_type  'Panalytical XPert MPD Pro'
_diffrn_radiation_type           'Cu K\a~1~'
_diffrn_radiation_wavelength     1.54176
_exptl_crystal_density_diffrn    5.2387
_exptl_crystal_density_method    'not measured'
_exptl_crystal_F_000             796
_pd_block_diffractogram_id       cacesioprofile
_pd_char_colour                  brown
_pd_char_particle_morphology     plate-like
_pd_meas_2theta_range_inc        0.017
_pd_meas_2theta_range_max        130.010
_pd_meas_2theta_range_min        10.023
_pd_meas_number_of_points        6881
_pd_meas_scan_method             step
_pd_prep_cool_rate               30
_pd_prep_pressure                100
_pd_prep_temperature             1873
_pd_proc_ls_background_function  'Legendre polynoms'
_pd_proc_ls_profile_function     pseudo-Voigt
_pd_proc_ls_prof_R_factor        0.0453
_pd_proc_ls_prof_wR_expected     0.0336
_pd_proc_ls_prof_wR_factor       0.0593
_pd_spec_mounting                ' packed powder pellet'
_pd_spec_mount_mode              reflection
_pd_spec_shape                   flat_sheet
_pd_spec_size_axial              25
_pd_spec_size_equat              25
_pd_spec_size_thick              1
_refine_diff_density_max         3.87
_refine_diff_density_min         -1.88
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_all   1.76
_refine_ls_goodness_of_fit_ref   1.76
_refine_ls_number_constraints    9
_refine_ls_number_parameters     28
_refine_ls_number_restraints     0
_refine_ls_R_factor_all          0.0458
_refine_ls_R_factor_gt           0.0438
_refine_ls_shift/su_max          0.0054
_refine_ls_shift/su_mean         0.0014
_refine_ls_weighting_scheme      sigma
_refine_ls_wR_factor_all         0.0442
_refine_ls_wR_factor_gt          0.0438
_cod_data_source_file            wm5448sup1.cif
_cod_data_source_block           I
_cod_database_code               2242532