Thortveitite-type Tm~2~Si~2~O~7~
Kahlenberg, Volker; Aichholzer, Paul; Acta Crystallographica Section E 70 (2014) i34–i35; doi:10.1107/S1600536814013142

data_2239660
_publ_section_title
;
 Thortveitite-type Tm~2~Si~2~O~7~
;
_journal_coeditor_code           WM5029
_journal_issue                   7
_journal_name_full               'Acta Crystallographica Section E'
_journal_page_first              i34
_journal_page_last               i35
_journal_paper_doi               10.1107/S1600536814013142
_journal_volume                  70
_journal_year                    2014
_chemical_formula_iupac          'Tm2 Si2 O7'
_chemical_formula_moiety         'O7 Si2 Tm2'
_chemical_formula_sum            'O7 Si2 Tm2'
_chemical_formula_weight         506.04
_chemical_name_systematic
;
Dithulium disilicate
;
_space_group_IT_number           12
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  '-C 2y'
_symmetry_space_group_name_H-M   'C 1 2/m 1'
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_conform_dict_name         cif_core.dic
_audit_conform_dict_version      2.4
_audit_creation_method           'WinGX routine CIF_UPDATE'
_cell_angle_alpha                90
_cell_angle_beta                 101.78(2)
_cell_angle_gamma                90
_cell_formula_units_Z            2
_cell_length_a                   6.8205(14)
_cell_length_b                   8.9062(18)
_cell_length_c                   4.6937(11)
_cell_measurement_reflns_used    762
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      29.3029
_cell_measurement_theta_min      3.8064
_cell_volume                     279.11(11)
_computing_cell_refinement
;
<i>CrysAlis PRO</i> (Agilent, 2014)
;
_computing_data_collection
;
<i>CrysAlis PRO</i> (Agilent, 2014)
;
_computing_data_reduction
;
<i>CrysAlis PRO</i> (Agilent, 2014)
;
_computing_molecular_graphics    'ATOMS for Windows (Dowty, 2011)'
_computing_publication_material
'publCIF (Westrip, 2010) and WinGX (Farrugia, 2012)'
_computing_structure_refinement  'SHELXL97 (Sheldrick, 2008)'
_computing_structure_solution    'SIR2002 (Burla <i>et al.</i>, 2003)'
_diffrn_ambient_temperature      293(2)
_diffrn_detector_area_resol_mean 10.3575
_diffrn_measured_fraction_theta_full 0.983
_diffrn_measured_fraction_theta_max 0.983
_diffrn_measurement_device       'four-circle diffractometer'
_diffrn_measurement_device_type  'Agilent Xcalibur (Ruby, Gemini ultra)'
_diffrn_measurement_method       '\w scans'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0203
_diffrn_reflns_limit_h_max       8
_diffrn_reflns_limit_h_min       -8
_diffrn_reflns_limit_k_max       11
_diffrn_reflns_limit_k_min       -11
_diffrn_reflns_limit_l_max       6
_diffrn_reflns_limit_l_min       -4
_diffrn_reflns_number            894
_diffrn_reflns_theta_full        27.63
_diffrn_reflns_theta_max         27.63
_diffrn_reflns_theta_min         3.81
_exptl_absorpt_coefficient_mu    31.992
_exptl_absorpt_correction_T_max  1
_exptl_absorpt_correction_T_min  0.23135
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
(<i>CrysAlis PRO</i>; Agilent, 2014)
;
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    6.021
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       'platy fragment'
_exptl_crystal_F_000             444
_exptl_crystal_size_max          0.05
_exptl_crystal_size_mid          0.03
_exptl_crystal_size_min          0.01
_refine_diff_density_max         1.624
_refine_diff_density_min         -1.423
_refine_ls_extinction_coef       0.0072(6)
_refine_ls_extinction_expression Fc^*^=kFc[1+0.001xFc^2^\l^3^/sin(2\q)]^-1/4^
_refine_ls_extinction_method     'SHELXL97 (Sheldrick, 2008)'
_refine_ls_goodness_of_fit_ref   1.154
_refine_ls_hydrogen_treatment    noref
_refine_ls_matrix_type           full
_refine_ls_number_parameters     32
_refine_ls_number_reflns         340
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.154
_refine_ls_R_factor_all          0.0188
_refine_ls_R_factor_gt           0.018
_refine_ls_shift/su_max          0
_refine_ls_shift/su_mean         0
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0265P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.045
_refine_ls_wR_factor_ref         0.0454
_reflns_number_gt                330
_reflns_number_total             340
_reflns_threshold_expression     I>2sigma(I)
_cod_data_source_file            wm5029sup1.cf
_cod_data_source_block           I
_cod_original_cell_volume        279.11(10)
_cod_original_sg_symbol_H-M      'C 2/m'
_cod_database_code               2239660
_cod_database_fobs_code          2239660