Modulation of quartz-like GeO~2~ structure by Si substitution: an X-ray diffraction study of Ge~1{-~<i>x</i>}Si<i>~x~</i>O~2~ (0 {łeq} <i>x</i> < 0.2) flux-grown single crystals
Lignie, Adrien; Granier, Dominique; Armand, Pascale; Haines, Julien; Papet, Philippe; Journal of Applied Crystallography 45 (2012) 272–278; doi:10.1107/S0021889812003081

data_2300370
_publ_section_title
;
 Modulation of quartz-like GeO~2~ structure by Si substitution: an X-ray
 diffraction study of Ge~1{-~<i>x</i>}Si<i>~x~</i>O~2~ (0 {\/leq} <i>x</i>
 < 0.2) flux-grown single crystals
;
_journal_issue                   2
_journal_name_full               'Journal of Applied Crystallography'
_journal_page_first              272
_journal_page_last               278
_journal_paper_doi               10.1107/S0021889812003081
_journal_volume                  45
_journal_year                    2012
_chemical_formula_sum            'O2 Si'
_chemical_formula_weight         60.09
_space_group_IT_number           154
_symmetry_space_group_name_Hall  'P 32 2"'
_symmetry_space_group_name_H-M   'P 32 2 1'
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_audit_update_record
;
2011-10-20 # Formatted by publCIF
;
_cell_angle_alpha                90.00
_cell_angle_beta                 90.00
_cell_angle_gamma                120.00
_cell_formula_units_Z            3
_cell_length_a                   4.91636(19)
_cell_length_b                   4.91636(18)
_cell_length_c                   5.4084(2)
_cell_measurement_temperature    298(2)
_cell_measurement_theta_max      34.7074
_cell_measurement_theta_min      3.7534
_cell_volume                     113.211(7)
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 2008)'
_diffrn_ambient_temperature      298(2)
_diffrn_measured_fraction_theta_full 0.976
_diffrn_measured_fraction_theta_max 0.976
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0293
_diffrn_reflns_av_sigmaI/netI    0.0077
_diffrn_reflns_limit_h_max       7
_diffrn_reflns_limit_h_min       -7
_diffrn_reflns_limit_k_max       7
_diffrn_reflns_limit_k_min       -7
_diffrn_reflns_limit_l_max       8
_diffrn_reflns_limit_l_min       -8
_diffrn_reflns_number            7027
_diffrn_reflns_theta_full        34.76
_diffrn_reflns_theta_max         34.76
_diffrn_reflns_theta_min         4.79
_exptl_absorpt_coefficient_mu    0.994
_exptl_absorpt_correction_T_max  0.899
_exptl_absorpt_correction_T_min  0.782
_exptl_absorpt_correction_type   gaussian
_exptl_absorpt_process_details
;
CrysAlisPro_Software_system,_Version_1.171.32.
;
_exptl_crystal_density_diffrn    2.644
_exptl_crystal_density_method    'not measured'
_exptl_crystal_F_000             90
_exptl_crystal_size_max          0.3392
_exptl_crystal_size_mid          0.1979
_exptl_crystal_size_min          0.1445
_refine_diff_density_max         0.210
_refine_diff_density_min         -0.262
_refine_diff_density_rms         0.064
_refine_ls_abs_structure_details 'Flack H D (1983), 113 Friedel pairs'
_refine_ls_abs_structure_Flack   -0.02(17)
_refine_ls_extinction_coef       12.8(4)
_refine_ls_extinction_expression Fc^*^=kFc[1+0.001xFc^2^\l^3^/sin(2\q)]^-1/4^
_refine_ls_extinction_method     SHELXL
_refine_ls_goodness_of_fit_ref   1.253
_refine_ls_matrix_type           full
_refine_ls_number_parameters     16
_refine_ls_number_reflns         319
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.253
_refine_ls_R_factor_all          0.0132
_refine_ls_R_factor_gt           0.0131
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0238P)^2^+0.0151P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0401
_refine_ls_wR_factor_ref         0.0402
_reflns_number_gt                318
_reflns_number_total             319
_reflns_threshold_expression     >2\s(I)
_cod_data_source_file            ce5127.cif
_cod_data_source_block           SiO2
_cod_original_cell_volume        113.210(7)
_cod_original_sg_symbol_H-M      P_32_2_1
_cod_database_code               2300370