Crystal structures of octasodium dieuropium(II) bis[hexa-tellurodisilicate], Na~8~Eu~2~[Si~2~Te~6~]~2~, octasodium dieuro- pium(II) bis[hexaselenodigermanate], Na~8~Eu~2~[Ge~2~Se~6~]~2~, and nonasodium samarium(III) bis[hexaselenodisilicate], Na~9~Sm[Si~2~Se~6~]~2~
Knaust, J. M.; Polyakova, L. A.; Dorhout, P. K.; Zeitschrift für Kristallographie - New Crystal Structures 220 (2005) 295–297; doi:

data_8102904
_publ_section_title
;
Crystal structures of octasodium dieuropium(II) bis[hexa-tellurodisilicate], 
Na~8~Eu~2~[Si~2~Te~6~]~2~, octasodium dieuro- pium(II) 
bis[hexaselenodigermanate], Na~8~Eu~2~[Ge~2~Se~6~]~2~, and nonasodium 
samarium(III) bis[hexaselenodisilicate], Na~9~Sm[Si~2~Se~6~]~2~
;
_journal_issue                   3
_journal_name_full
'Zeitschrift f\"ur Kristallographie - New Crystal Structures'
_journal_page_first              295
_journal_page_last               297
_journal_volume                  220
_journal_year                    2005
_chemical_formula_structural     'Na9 Sm [Si2 Se6]2'
_chemical_formula_sum            'Na9 Se12 Si4 Sm'
_chemical_formula_weight         1417.14
_chemical_name_systematic
; 
nonasodium samarium(III) bis[hexaselenodisilicate(III)]
;
_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_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_cell_angle_alpha                90.00
_cell_angle_beta                 107.178(3)
_cell_angle_gamma                90.00
_cell_formula_units_Z            1
_cell_length_a                   7.0109(13)
_cell_length_b                   12.098(2)
_cell_length_c                   7.9160(15)
_cell_measurement_reflns_used    1376
_cell_measurement_temperature    173(2)
_cell_measurement_theta_max      28.2565
_cell_measurement_theta_min      2.793
_cell_volume                     641.5(2)
_computing_cell_refinement       'SMART, Bruker'
_computing_data_collection       'SMART, Bruker'
_computing_data_reduction        'SAINT, Bruker'
_computing_molecular_graphics    'X-Seed (Barbour, 1999)'
_computing_publication_material  'X-Seed (Barbour, 1999)'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1997)'
_diffrn_ambient_temperature      298(2)
_diffrn_measured_fraction_theta_full 0.971
_diffrn_measured_fraction_theta_max 0.971
_diffrn_measurement_device_type  'Bruker AXS SMART CCD'
_diffrn_measurement_method       phi/omega
_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  0.0349
_diffrn_reflns_av_sigmaI/netI    0.0436
_diffrn_reflns_limit_h_max       9
_diffrn_reflns_limit_h_min       -9
_diffrn_reflns_limit_k_max       15
_diffrn_reflns_limit_k_min       -15
_diffrn_reflns_limit_l_max       8
_diffrn_reflns_limit_l_min       -10
_diffrn_reflns_number            1985
_diffrn_reflns_theta_full        28.26
_diffrn_reflns_theta_max         28.26
_diffrn_reflns_theta_min         2.69
_exptl_absorpt_coefficient_mu    19.643
_exptl_absorpt_correction_T_max  1.0000000
_exptl_absorpt_correction_T_min  0.4441228
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
; 
Data were collected for decay and absorption using the program SADABS
based on the method of R.H. Blessing (Acta Cryst. A51, 33-38, 1995). 
;
_exptl_crystal_colour            yellow
_exptl_crystal_density_diffrn    3.669
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       'thick plate'
_exptl_crystal_F_000             625
_refine_diff_density_max         1.466
_refine_diff_density_min         -3.538
_refine_diff_density_rms         0.471
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.202
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     36
_refine_ls_number_reflns         808
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.202
_refine_ls_R_factor_all          0.0557
_refine_ls_R_factor_gt           0.0509
_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^)+(0.0655P)^2^+0.9627P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1156
_refine_ls_wR_factor_ref         0.1194
_reflns_number_gt                725
_reflns_number_total             808
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            409829.cff
_cod_data_source_block           Na9SmSi4Se12
_cod_database_code               8102904