data_global _chemical_name_mineral 'Omphacite' loop_ _publ_author_name 'Pavese A' 'Bocchio R' 'Ivaldi G' _journal_name_full 'Mineralogical Magazine' _journal_volume 64 _journal_year 2000 _journal_page_first 983 _journal_page_last 993 _publ_section_title ; In situ high temperature single crystal X-ray diffraction study of a natural omphacite Note: structure at room temperature (T=298K), after being heated to 1073K ; _database_code_amcsd 0014549 _chemical_compound_source 'Gorduno, Lepontine Alps, Switzerland' _chemical_formula_sum '(Ca.5 Na.5) Mg.46 Al.51 Fe.06 Si1.97 O6' _cell_length_a 9.563 _cell_length_b 8.776 _cell_length_c 5.254 _cell_angle_alpha 90 _cell_angle_beta 106.90 _cell_angle_gamma 90 _cell_volume 421.899 _exptl_crystal_density_diffrn 3.324 _symmetry_space_group_name_H-M 'P 1 2/n 1' loop_ _space_group_symop_operation_xyz 'x,y,z' '1/2-x,y,1/2-z' '1/2+x,-y,1/2+z' '-x,-y,-z' loop_ _atom_site_label _atom_site_fract_x _atom_site_fract_y _atom_site_fract_z _atom_site_occupancy _atom_site_U_iso_or_equiv CaM2 0.75000 0.05220 0.25000 0.31000 0.01030 NaM2 0.75000 0.05220 0.25000 0.69000 0.01030 CaM21 0.75000 0.45010 0.75000 0.69000 0.01140 NaM21 0.75000 0.45010 0.75000 0.31000 0.01140 MgM1 0.75000 0.65870 0.25000 0.46000 0.00690 AlM1 0.75000 0.65870 0.25000 0.48000 0.00690 FeM1 0.75000 0.65870 0.25000 0.06000 0.00690 MgM11 0.75000 0.84716 0.75000 0.46000 0.00390 AlM11 0.75000 0.84716 0.75000 0.48000 0.00390 FeM11 0.75000 0.84716 0.75000 0.06000 0.00390 SiT1 0.03924 0.84712 0.22690 0.98500 0.00480 AlT1 0.03924 0.84712 0.22690 0.01500 0.00480 SiT2 0.03737 0.66177 0.73020 0.98500 0.00470 AlT2 0.03737 0.66177 0.73020 0.01500 0.00470 O11 0.86280 0.83790 0.12150 1.00000 0.00790 O12 0.86100 0.67700 0.64650 1.00000 0.00790 O21 0.11420 0.00970 0.30860 1.00000 0.00860 O22 0.10640 0.49700 0.80490 1.00000 0.00950 O31 0.10600 0.76600 0.00390 1.00000 0.00730 O32 0.09840 0.73990 0.49760 1.00000 0.00740