Mixed Alkali Systems: Structure and ^29^Si MASNMR of Li~2~Si~2~O~5~ and K~2~Si~2~O~5~
de Jong, B. H. W. S.; Supèr, H. T. J.; Spek, A. L.; Veldman, N.; Nachtegaal, G.; Fischer, J. C.; Acta Crystallographica Section B 54 (1998) 568–577; doi:10.1107/S0108768198001062

data_2003026
_publ_section_title
;
 Mixed Alkali Systems: Structure and ^29^Si MASNMR of Li~2~Si~2~O~5~
 and K~2~Si~2~O~5~
;
_journal_issue                   5
_journal_name_full               'Acta Crystallographica Section B'
_journal_page_first              568
_journal_page_last               577
_journal_paper_doi               10.1107/S0108768198001062
_journal_volume                  54
_journal_year                    1998
_chemical_formula_moiety         'K2 Si2 O5'
_chemical_formula_sum            'K2 O5 Si2'
_chemical_formula_weight         214.36
_chemical_name_systematic
;
 Potassium disilicate
;
_space_group_IT_number           9
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  'C -2yc'
_symmetry_space_group_name_H-M   'C 1 c 1'
_cell_angle_alpha                90
_cell_angle_beta                 115.972(11)
_cell_angle_gamma                90
_cell_formula_units_Z            12
_cell_length_a                   16.3224(15)
_cell_length_b                   11.243(2)
_cell_length_c                   9.9190(10)
_cell_measurement_reflns_used    25
_cell_measurement_temperature    150
_cell_measurement_theta_max      14
_cell_measurement_theta_min      10
_cell_volume                     1636.4(4)
_computing_publication_material  'PLATON (Spek, 1990)'
_computing_structure_refinement  'SHELXL-96 (Sheldrick, 1996)'
_diffrn_ambient_temperature      150
_diffrn_measurement_device_type  CAD4-T
_diffrn_measurement_method       \w-scan
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'Rotating Anode'
_diffrn_radiation_type           'Mo K\a'
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0472
_diffrn_reflns_av_sigmaI/netI    0.0656
_diffrn_reflns_limit_h_max       21
_diffrn_reflns_limit_h_min       -12
_diffrn_reflns_limit_k_max       12
_diffrn_reflns_limit_k_min       -14
_diffrn_reflns_limit_l_max       12
_diffrn_reflns_limit_l_min       -12
_diffrn_reflns_number            3875
_diffrn_reflns_theta_max         27.48
_diffrn_reflns_theta_min         2.28
_diffrn_standards_decay_%        0
_diffrn_standards_interval_time  60
_diffrn_standards_number         1
_exptl_absorpt_coefficient_mu    2.11
_exptl_absorpt_correction_T_max  1.000
_exptl_absorpt_correction_T_min  0.655
_exptl_absorpt_correction_type   'delabs (Spek, 1990)'
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    2.610
_exptl_crystal_density_meas      ?
_exptl_crystal_description       'irregular plate'
_exptl_crystal_F_000             1272
_exptl_crystal_size_max          0.25
_exptl_crystal_size_mid          0.25
_exptl_crystal_size_min          0.05
_refine_diff_density_max         0.644
_refine_diff_density_min         -0.671
_refine_ls_abs_structure_details 'Flack H.D. (1983), Acta Cryst. A39, 876-881'
_refine_ls_extinction_method     none
_refine_ls_hydrogen_treatment    'H-atom refinement: see text '
_refine_ls_matrix_type           full
_refine_ls_number_parameters     245
_refine_ls_number_reflns         2711
_refine_ls_restrained_S_all      1.031
_refine_ls_restrained_S_obs      1.048
_refine_ls_R_factor_all          0.038
_refine_ls_R_factor_gt           0.038
_refine_ls_shift/esd_mean        0.000
_refine_ls_shift/su_max          0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w = 1/[\s^2^(Fo^2^)+( 0.0304P)^2^]         where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_all         0.079
_refine_ls_wR_factor_ref         0.079
_reflns_number_gt                2370
_reflns_number_total             2711
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            na0083.cif
_cod_data_source_block           S1295B
_cod_depositor_comments
;
The following automatic conversions were performed:
'_symmetry_cell_setting' value 'Monoclinic' changed to 'monoclinic'
according to '/home/saulius/struct/CIF-dictionaries/cif_core.dic'
dictionary named 'cif_core.dic' version 2.4.1 from 2010-06-29.

Automatic conversion script
Id: cif_fix_enum 1527 2010-12-29 10:47:43Z saulius 

The following automatic conversions were performed:

'_symmetry_cell_setting' value 'Monoclinic' changed to 'monoclinic'
according to /home/saulius/struct/CIF-dictionaries/cif_core.dic
dictionary named 'cif_core.dic' version 2.4.1 from 2010-06-29.

Automatic conversion script
Id: cif_fix_values 1715 2011-07-08 13:25:40Z adriana 

The following automatic conversions were performed:

'_refine_ls_weighting_scheme' value 'w = 1/[\s^2^(Fo^2^)+(
0.0304P)^2^] where P=(Fo^2^+2Fc^2^)/3' was changed to 'calc'. New tag
'_refine_ls_weighting_details' was created. The value of the new tag
was set to 'w = 1/[\s^2^(Fo^2^)+( 0.0304P)^2^] where
P=(Fo^2^+2Fc^2^)/3'.

Automatic conversion script
Id: cif_fix_values 3143 2015-03-26 13:38:13Z robertas 
;
_cod_original_sg_symbol_H-M      'C c'
_cod_database_code               2003026