 
data_melanophlogite
  
_audit_creation_method            SHELXL-97
_chemical_name_systematic
;
 ?
;
_chemical_name_common             ?
_chemical_melting_point           ?
_chemical_formula_moiety          ?
_chemical_formula_sum
 'C0.17 O2 Si'
_chemical_formula_weight          62.18
 
loop_
 _atom_type_symbol
 _atom_type_description
 _atom_type_scat_dispersion_real
 _atom_type_scat_dispersion_imag
 _atom_type_scat_source
 'O'  'O'   0.0106   0.0060
 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4'
 'Si'  'Si'   0.0817   0.0704
 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4'
 'C'  'C'   0.0033   0.0016
 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4'
 
_symmetry_cell_setting            'cubic'
_symmetry_space_group_name_H-M    'P m -3 n'
 
loop_
 _symmetry_equiv_pos_as_xyz
 'x, y, z'
 'x, -y, -z'
 '-x, -y, z'
 '-x, y, -z'
 '-y+1/2, x+1/2, z+1/2'
 'y+1/2, x+1/2, -z+1/2'
 'y+1/2, -x+1/2, z+1/2'
 '-y+1/2, -x+1/2, -z+1/2'
 'y, z, x'
 '-y, -z, x'
 'y, -z, -x'
 '-y, z, -x'
 '-z+1/2, y+1/2, x+1/2'
 '-z+1/2, -y+1/2, -x+1/2'
 'z+1/2, -y+1/2, x+1/2'
 'z+1/2, y+1/2, -x+1/2'
 'z, x, y'
 '-z, x, -y'
 '-z, -x, y'
 'z, -x, -y'
 '-x+1/2, -z+1/2, -y+1/2'
 '-x+1/2, z+1/2, y+1/2'
 'x+1/2, -z+1/2, y+1/2'
 'x+1/2, z+1/2, -y+1/2'
 '-x, -y, -z'
 '-x, y, z'
 'x, y, -z'
 'x, -y, z'
 'y-1/2, -x-1/2, -z-1/2'
 '-y-1/2, -x-1/2, z-1/2'
 '-y-1/2, x-1/2, -z-1/2'
 'y-1/2, x-1/2, z-1/2'
 '-y, -z, -x'
 'y, z, -x'
 '-y, z, x'
 'y, -z, x'
 'z-1/2, -y-1/2, -x-1/2'
 'z-1/2, y-1/2, x-1/2'
 '-z-1/2, y-1/2, -x-1/2'
 '-z-1/2, -y-1/2, x-1/2'
 '-z, -x, -y'
 'z, -x, y'
 'z, x, -y'
 '-z, x, y'
 'x-1/2, z-1/2, y-1/2'
 'x-1/2, -z-1/2, -y-1/2'
 '-x-1/2, z-1/2, -y-1/2'
 '-x-1/2, -z-1/2, y-1/2'
 
_cell_length_a                    13.399(2)
_cell_length_b                    13.399(2)
_cell_length_c                    13.399(2)
_cell_angle_alpha                 90.00
_cell_angle_beta                  90.00
_cell_angle_gamma                 90.00
_cell_volume                      2405.6(7)
_cell_formula_units_Z             46
_cell_measurement_temperature     293
_cell_measurement_reflns_used     3000
_cell_measurement_theta_min       5
_cell_measurement_theta_max       28
 
_exptl_crystal_description        cubic
_exptl_crystal_colour             colourless
_exptl_crystal_size_max           0.25
_exptl_crystal_size_mid           0.25
_exptl_crystal_size_min           0.25
_exptl_crystal_density_meas       ?
_exptl_crystal_density_diffrn     1.974
_exptl_crystal_density_method     'not measured'
_exptl_crystal_F_000              1428
_exptl_absorpt_coefficient_mu     0.721
_exptl_absorpt_correction_type    none

 
_exptl_special_details
;
 ?
;
 
_diffrn_ambient_temperature       293(2)
_diffrn_radiation_wavelength      0.71073
_diffrn_radiation_type            MoK\a
_diffrn_radiation_source          'fine-focus sealed tube'
_diffrn_radiation_monochromator   graphite
_diffrn_measurement_device_type   'Smart CCD  Brucker diffractometer'
_diffrn_measurement_method        'profile data from area detector'
_diffrn_detector_area_resol_mean  ?
_diffrn_standards_number          100
_diffrn_standards_interval_count  ?
_diffrn_standards_interval_time   ?
_diffrn_standards_decay_%         98
_diffrn_reflns_number             6317
_diffrn_reflns_av_R_equivalents   0.0000
_diffrn_reflns_av_sigmaI/netI     0.0381
_diffrn_reflns_limit_h_min        -17
_diffrn_reflns_limit_h_max        17
_diffrn_reflns_limit_k_min        -16
_diffrn_reflns_limit_k_max        12
_diffrn_reflns_limit_l_min        -17
_diffrn_reflns_limit_l_max        7
_diffrn_reflns_theta_min          2.15
_diffrn_reflns_theta_max          28.47
_reflns_number_total              6317
_reflns_number_gt                 4523
_reflns_threshold_expression      >2sigma(I)
 
_computing_data_collection        ?
_computing_cell_refinement        ?
_computing_data_reduction         ?
_computing_structure_solution     ?
_computing_structure_refinement   'SHELXL-97 (Sheldrick, 1997)'
_computing_molecular_graphics     ?
_computing_publication_material   ?
 
_refine_special_details
;
 Refinement with redundant (i.e. not merged/unique) data set.
 Refinement of F² against ALL reflections.  The weighted R-factor wR and
 goodness of fit S are based on F², conventional R-factors R are based
 on F, with F set to zero for negative F². The threshold expression of
 F² > 2sigma(F²) is used only for calculating R-factors(gt) etc. and is
 not relevant to the choice of reflections for refinement.  R-factors based
 on F² are statistically about twice as large as those based on F, and R-
 factors based on ALL data will be even larger.
;
 
_refine_ls_structure_factor_coef  Fsqd
_refine_ls_matrix_type            full
_refine_ls_weighting_scheme       calc
_refine_ls_weighting_details
 'calc w=1/[σ²(Fo²)+(0.0601P)²+16.3830P] where P=(Fo²+2Fc²)/3'
_atom_sites_solution_primary      direct
_atom_sites_solution_secondary    difmap
_atom_sites_solution_hydrogens    .
_refine_ls_hydrogen_treatment     .
_refine_ls_extinction_method      none
_refine_ls_extinction_coef        ?
_refine_ls_number_reflns          6317
_refine_ls_number_parameters      38
_refine_ls_number_restraints      0
_refine_ls_R_factor_all           0.0868
_refine_ls_R_factor_gt            0.0635
_refine_ls_wR_factor_ref          0.1525
_refine_ls_wR_factor_gt           0.1410
_refine_ls_goodness_of_fit_ref    0.916
_refine_ls_restrained_S_all       0.916
_refine_ls_shift/su_max           0.000
_refine_ls_shift/su_mean          0.000
 
loop_
 _atom_site_label
 _atom_site_type_symbol
 _atom_site_fract_x
 _atom_site_fract_y
 _atom_site_fract_z
 _atom_site_U_iso_or_equiv
 _atom_site_adp_type
 _atom_site_occupancy
 _atom_site_symmetry_multiplicity
Si1 Si 0.0000 0.31068 0.11429 0.03395 Uani 1 2 
Si2 Si 0.18260 0.18260 0.18260 0.03132 Uani 1 3 
Si3 Si 0.2500 0.0000 0.5000 0.0218 Uani 1 8 
O1 O 0.09612 0.24655 0.13558 0.0726 Uani 1 1 
O2 O 0.0000 0.40624 0.18129 0.0891 Uani 1 2 
O3 O 0.34376 0.0000 0.0000 0.0410 Uani 1 4 
O4 O 0.2500 0.2500 0.2500 0.0914 Uani 1 6 
C1 C 0.0000 0.0000 0.0000 0.088 Uani 1.21 24 
C2 C 0.5000 0.0000 0.2500 0.311 Uani 1.56 8 
loop_
 _atom_site_aniso_label
 _atom_site_aniso_U_11
 _atom_site_aniso_U_22
 _atom_site_aniso_U_33
 _atom_site_aniso_U_23
 _atom_site_aniso_U_13
 _atom_site_aniso_U_12
Si1 0.0430 0.0249 0.0339 -0.0071 0.000 0.000
Si2 0.03132 0.03132 0.03132 -0.00513 -0.00513 -0.00513
Si3 0.0177 0.0239 0.0239 0.000 0.000 0.000
O1 0.0642 0.0852 0.0684 0.0122 -0.0109 0.0325
O2 0.169 0.0391 0.0590 -0.0308 0.000 0.000
O3 0.0340 0.0381 0.0510 0.000 0.000 0.000
O4 0.0914 0.0914 0.0914 -0.0373 -0.0373 -0.0373
C1 0.088 0.088 0.088 0.000 0.000 0.000
C2 0.387 0.387 0.158 0.000 0.000 0.000
 
_geom_special_details
;
 All esds (except the esd in the dihedral angle between two l.s. planes)
 are estimated using the full covariance matrix.  The cell esds are taken
 into account individually in the estimation of esds in distances, angles
 and torsion angles; correlations between esds in cell parameters are only
 used when they are defined by crystal symmetry.  An approximate (isotropic)
 treatment of cell esds is used for estimating esds involving l.s. planes.
;
_geom_bond_atom_site_label_1 Si1 
_geom_angle_atom_site_label_2 O1
_geom_bond_distance 1.5759


 
_diffrn_measured_fraction_theta_max    0.974
_diffrn_reflns_theta_full              28.47
_diffrn_measured_fraction_theta_full   0.974
_refine_diff_density_max    0.568
_refine_diff_density_min   -0.368
_refine_diff_density_rms    0.087
_publ_section_exptl_refinement 
'C1 and C2 ref. as C and higher than 1 to estimate the electron occupancy.' 
_publ_contact_author_name 'Mario Tribaudino'
_publ_contact_author_address 'Dipartimento di Scienze della Terra'
_publ_contact_author_email 'mario.tribaudino@unipr.it'
_publ_contact_author_fax '00390521905340'
_publ_contact_author_phone '00390521905340'
_publ_section_abstract  'English'
_publ_requested_journal 'American Mineralogist'