High-Temperature, High-Pressure Hydrothermal Synthesis and Characterization of a Salt-Inclusion Mixed-Valence Uranium(V,VI) Silicate: [Na9F2][(UVO2)(UVIO2)2(Si2O7)2]
Yu-Chih Chang; Wen-Jung Chang; Sophie Boudin; Kwang-Hwa Lii; Inorganic Chemistry 52 (2013) 7230–7235; doi:10.1021/ic400854j

data_4335253
_publ_section_title
;
 High-Temperature, High-Pressure Hydrothermal Synthesis and
 Characterization of a Salt-Inclusion Mixed-Valence Uranium(V,VI)
 Silicate: [Na9F2][(UVO2)(UVIO2)2(Si2O7)2]
;
_journal_name_full               'Inorganic Chemistry'
_journal_page_first              7230
_journal_page_last               7235
_journal_paper_doi               10.1021/ic400854j
_journal_volume                  52
_journal_year                    2013
_chemical_formula_structural     Na9F2(UO2)(UO2)2(Si2O7)2
_chemical_formula_sum            'F2 Na9 O20 Si4 U3'
_space_group_crystal_system      triclinic
_space_group_IT_number           2
_space_group_name_H-M_alt        'P -1'
_symmetry_space_group_name_Hall  '-P 1'
_symmetry_space_group_name_H-M   'P -1'
_cell_angle_alpha                90.41(1)
_cell_angle_beta                 94.96(1)
_cell_angle_gamma                90.01(2)
_cell_formula_units_Z            1
_cell_length_a                   5.842(1)
_cell_length_b                   7.411(2)
_cell_length_c                   11.902(1)
_cell_volume                     513.35(17)
_computing_structure_refinement  'Fullprof Suite 1.00 (Feb 2007)'
_diffrn_ambient_temperature      293
_diffrn_measurement_device_type  'X'Pert Pro Panalytical Philips'
_diffrn_radiation_type           'Cu K\a'
_diffrn_radiation_wavelength     1.5418
_diffrn_source_type              'x-ray tube'
_exptl_crystal_density_diffrn    4.50
_pd_calc_method                  'Rietveld refinement'
_pd_char_colour                  green
_pd_meas_2theta_range_inc        0.013132
_pd_meas_2theta_range_max        90.049461
_pd_meas_2theta_range_min        5.124620
_pd_meas_number_of_points        6464
_pd_meas_scan_method             step
_pd_proc_2theta_range_inc        0.013132
_pd_proc_2theta_range_max        90.04946
_pd_proc_2theta_range_min        5.124620
_pd_proc_ls_pref_orient_corr
;
Preferred orientation (March Model) defined as follows :
Ph = [(G1 cos (alpha,h))^2 +((sin (alpha,h))^2 /G1)]^1.5
Ph : preferred orientation correction for the h reflection
alpha,h : acute angle between the scattering vector and the normal to the
crystallites
G1 preferred orientation coefficient ; G1 = 0.4782(2)
h = 001
;
_pd_proc_ls_profile_function
;
Profile function : Pseudo-Voigt function, pV(x) defined as follows :
pV(x) = Eta L(x) + (1-Eta)G(x)
with 
x = 2thetai * 2thetah; thetai, thetah: theta angle of the ith measured
 step and of the h reflection.
L(x), G(x) : Lorentzian and gaussian function
Eta = Lorentzian ratio
and with
FWHM = U tan^2(theta) + V tan(theta) + W    for L(x) and G(x)
Eta = 0.914(3)
U = 2.23(1)
V = -1.016(5)
W = 0.1267(6)

Asymmetry correction applied up to 2theta=28\% as follows :
A(x)= 1 + ((P1.F1(x)+P2.F2(x))/tanh(thetah))
with
x = 2thetai *  2thetah; 
thetai,thetah: theta angle of the ith measured step and of the h reflection.
F1(x)=2x.exp(-x^2) and F2(x)=2(2x^2-3).F1(x)
P1 = 0.02380(4)
P2 = 0.01435(1)
;
_pd_proc_ls_prof_R_factor        0.1210
_pd_proc_ls_prof_wR_expected     0.0550
_pd_proc_ls_prof_wR_factor       0.1640
_pd_proc_number_of_points        6464
_pd_spec_mount_mode              reflection
_pd_spec_shape                   flat_sheet
_refine_diff_density_max         2.77
_refine_diff_density_min         -1.20
_refine_ls_goodness_of_fit_all   0.0871
_refine_ls_number_constraints    0
_refine_ls_number_parameters     86
_refine_ls_number_restraints     0
_refine_ls_R_factor_all          0.0322
_refine_ls_R_I_factor            0.0703
_refine_ls_shift/su_max          0.83
_refine_ls_weighting_scheme      sigma
_reflns_limit_h_max              5
_reflns_limit_h_min              -5
_reflns_limit_k_max              6
_reflns_limit_k_min              -6
_reflns_limit_l_max              10
_reflns_limit_l_min              0
_reflns_number_observed          886
_cod_data_source_file            ic400854j_si_003.cif
_cod_data_source_block           F2Na9O20Si4U3
_cod_original_cell_volume        513.4(2)
_cod_database_code               4335253
_cod_database_fobs_code          4335253
_pd_calib_2theta_offset'         0.0004(37)
_reflns_d_spacing_max            11.856631
_reflns_d_spacing_min            1.089737