Synthesis, structure, and polymorphism of A3LnSi2O7 (A=Na, K; Ln=Sm, Ho, Yb)
Latshaw, Allison M.; Yeon, Jeongho; Smith, Mark D.; zur Loye, Hans-Conrad; Journal of Solid State Chemistry 235 (2016) 100–106; doi:10.1016/j.jssc.2015.12.013

data_1561596
_publ_section_title
;
 Synthesis, structure, and polymorphism of A3LnSi2O7 (A=Na, K; Ln=Sm, Ho,
 Yb)
;
_journal_name_full               'Journal of Solid State Chemistry'
_journal_page_first              100
_journal_page_last               106
_journal_paper_doi               10.1016/j.jssc.2015.12.013
_journal_volume                  235
_journal_year                    2016
_chemical_formula_moiety         '0.17(Na18 O42 Si12 Yb6)'
_chemical_formula_sum            'Na3 O7 Si2 Yb'
_chemical_formula_weight         410.19
_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'
_atom_sites_solution_hydrogens   .
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                120
_cell_formula_units_Z            6
_cell_length_a                   9.3770(2)
_cell_length_b                   9.3770(2)
_cell_length_c                   13.7187(4)
_cell_measurement_temperature    294(2)
_cell_volume                     1044.65(4)
_computing_molecular_graphics    'Olex2 (Dolomanov et al., 2009)'
_computing_publication_material  'Olex2 (Dolomanov et al., 2009)'
_computing_structure_refinement  'ShelXL (Sheldrick, 2008)'
_diffrn_ambient_temperature      294.15
_diffrn_measured_fraction_theta_full 1.000
_diffrn_measured_fraction_theta_max 1.000
_diffrn_measurement_device_type  'CCD area detector'
_diffrn_measurement_method       'phi and omega scans'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0335
_diffrn_reflns_av_unetI/netI     0.0129
_diffrn_reflns_Laue_measured_fraction_full 1.000
_diffrn_reflns_Laue_measured_fraction_max 1.000
_diffrn_reflns_limit_h_max       12
_diffrn_reflns_limit_h_min       -12
_diffrn_reflns_limit_k_max       12
_diffrn_reflns_limit_k_min       -12
_diffrn_reflns_limit_l_max       18
_diffrn_reflns_limit_l_min       -18
_diffrn_reflns_number            14399
_diffrn_reflns_point_group_measured_fraction_full 1.000
_diffrn_reflns_point_group_measured_fraction_max 1.000
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         28.351
_diffrn_reflns_theta_min         2.508
_exptl_absorpt_coefficient_mu    13.954
_exptl_crystal_colour            'pale yellow'
_exptl_crystal_density_diffrn    3.912
_exptl_crystal_description       'hexagonal prism'
_exptl_crystal_F_000             1122
_exptl_crystal_size_max          0.16
_exptl_crystal_size_mid          0.08
_exptl_crystal_size_min          0.08
_refine_diff_density_max         0.736
_refine_diff_density_min         -0.811
_refine_diff_density_rms         0.141
_refine_ls_extinction_coef       0.0078(2)
_refine_ls_extinction_expression Fc^*^=kFc[1+0.001xFc^2^\l^3^/sin(2\q)]^-1/4^
_refine_ls_extinction_method     'SHELXL-2014/7 (Sheldrick 2014'
_refine_ls_goodness_of_fit_ref   1.273
_refine_ls_hydrogen_treatment    undef
_refine_ls_matrix_type           full
_refine_ls_number_parameters     64
_refine_ls_number_reflns         920
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.273
_refine_ls_R_factor_all          0.0143
_refine_ls_R_factor_gt           0.0142
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+4.2070P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0349
_refine_ls_wR_factor_ref         0.0349
_reflns_Friedel_coverage         0.000
_reflns_Friedel_fraction_full    .
_reflns_Friedel_fraction_max     .
_reflns_number_gt                917
_reflns_number_total             920
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            mmc3.cif
_cod_data_source_block           Na3YbSi2O7
_cod_original_cell_volume        1044.65(5)
_cod_database_code               1561596
_shelx_estimated_absorpt_t_max   0.401
_shelx_estimated_absorpt_t_min   0.214
_olex2_refinement_description
;
;
_shelx_res_checksum              1732
_shelx_hkl_checksum              60084
_shelx_shelxl_version_number     2014/7
_olex2_submission_special_instructions 'No special instructions were received'