data_global
_chemical_name_mineral 'Burpalite'
loop_
_publ_author_name
'Merlino S'
'Perchiazzi N'
'Khomyakov A P'
'Pushcharovsky D Y'
'Kulikova I M'
'Kuzmin V I'
_journal_name_full 'European Journal of Mineralogy'
_journal_volume 2 
_journal_year 1990
_journal_page_first 177
_journal_page_last 185
_publ_section_title
;
 Burpalite, a new mineral from Burpalinskii massif, North Transbajkal, USSR:
 its crystal structure and OD character
;
_database_code_amcsd 0006380
_chemical_compound_source 'Burpalinskii massif, North Transbajkal, USSR'
_chemical_formula_sum 'Na2 Ca Zr Si2 O7 F2'
_cell_length_a 10.1173
_cell_length_b 10.4446
_cell_length_c 7.2555
_cell_angle_alpha 90
_cell_angle_beta 90.039
_cell_angle_gamma 90
_cell_volume 766.697
_exptl_crystal_density_diffrn      3.322
_symmetry_space_group_name_H-M 'P 1 21/a 1'
loop_
_space_group_symop_operation_xyz
  'x,y,z'
  '1/2+x,1/2-y,z'
  '1/2-x,1/2+y,-z'
  '-x,-y,-z'
loop_
_atom_site_label
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
_atom_site_U_iso_or_equiv
Na1   0.37690  -0.07430  -0.12310   0.01988
Na2   0.37440  -0.07080   0.37590   0.01760
Ca   0.10520  -0.19990   0.12600   0.01634
Zr   0.10700  -0.19970   0.62470   0.01532
Si1   0.16710   0.12040  -0.34790   0.01355
Si2   0.17020   0.12150   0.09950   0.01317
O1   0.16810   0.14680  -0.12060   0.04091
O2   0.26580   0.23160   0.58300   0.02406
O3   0.26600   0.23910   0.16520   0.02837
O4   0.01890   0.14990   0.59090   0.02850
O5   0.01710   0.14690   0.15840   0.03154
O6   0.21480  -0.02610   0.61580   0.01811
O7   0.22430  -0.01730   0.13810   0.02508
F1   0.48940   0.11100  -0.12720   0.02634
F2   0.48370   0.12030   0.37450   0.02178
loop_
_atom_site_aniso_label
_atom_site_aniso_U_11
_atom_site_aniso_U_22
_atom_site_aniso_U_33
_atom_site_aniso_U_12
_atom_site_aniso_U_13
_atom_site_aniso_U_23
Na1 0.01610 0.02160 0.02190 -0.00730 -0.00020 0.00430
Na2 0.01710 0.02040 0.01520 0.00030 0.00010 -0.00320
Ca 0.01780 0.01550 0.01560 -0.00520 0.00060 0.00010
Zr 0.01480 0.01700 0.01410 0.00140 -0.00070 -0.00020
Si1 0.01240 0.01060 0.01770 0.00130 -0.00080 0.00010
Si2 0.00930 0.01130 0.01890 -0.00150 -0.00020 0.00050
O1 0.06390 0.04980 0.00910 0.01310 0.00380 0.00040
O2 0.01800 0.01580 0.03850 -0.00560 0.00860 -0.00520
O3 0.02040 0.02420 0.04050 -0.00350 -0.00100 -0.01170
O4 0.01750 0.02120 0.04690 0.00220 0.00250 0.00090
O5 0.01320 0.03630 0.04490 0.00550 0.00110 -0.00320
O6 0.01880 0.01740 0.01830 0.00370 0.00500 -0.00400
O7 0.03130 0.00900 0.03510 0.00480 -0.00710 0.00170
F1 0.03040 0.01800 0.03060 0.00380 -0.00050 -0.00210
F2 0.01720 0.01320 0.03510 0.00610 0.00060 0.00030