data_9002505
_chemical_name 'Cuspidine'
loop_
_publ_author_name
'Piotrowski A'
'Kahlenberg V'
'Fischer R X'
_journal_name_full "American Mineralogist"
_journal_volume 85
_journal_year 1999
_journal_page_first 1534
_journal_page_last 1539
_publ_section_title
;
 Na2Ca2(P2O7)F2, the first diphosphate of the cuspidine family
 Sample: split position O1
;
_chemical_formula_sum '(Ca1.005 Na.995) P F O3.5'
_cell_length_a 10.8730
_cell_length_b 10.5516
_cell_length_c 7.4287
_cell_angle_alpha 90
_cell_angle_beta 109.74
_cell_angle_gamma 90
_cell_volume 802.193
_symmetry_space_group_name_H-M 'P 1 21/n 1'
loop_
_symmetry_equiv_pos_as_xyz
  'x,y,z'
  '1/2+x,1/2-y,1/2+z'
  '1/2-x,1/2+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_Uiso_or_equiv
Ca1   0.57540   0.87670   0.66470   0.83000 ?
Na1   0.57540   0.87670   0.66470   0.17000 ?
Ca2   0.80700   0.10260   0.52770   0.45000 ?
Na2   0.80700   0.10260   0.52770   0.55000 ?
Ca3   0.81740   0.08350   0.03390   0.54000 ?
Na3   0.81740   0.08350   0.03390   0.46000 ?
Ca4   0.58190   0.88690   0.16250   0.19000 ?
Na4   0.58190   0.88690   0.16250   0.81000 ?
P1   0.12410   0.18320   0.64350   1.00000 ?
P2   0.62260   0.31720   0.72960   1.00000 ?
F1   0.61260   0.00220   0.92310   1.00000 ?
F2   0.60970   0.00510   0.43710   1.00000 ?
O1A   0.16700   0.21140   0.45460   0.50000   0.02840
O1B   0.07520   0.19770   0.41300   0.50000   0.02870
O2   0.84900   0.95410   0.78850   1.00000 ?
O3   0.99750   0.23200   0.65350   1.00000 ?
O4   0.15060   0.04580   0.68880   1.00000 ?
O5   0.99770   0.23000   0.09030   1.00000 ?
O6   0.73920   0.23530   0.74660   1.00000 ?
O7   0.23990   0.26590   0.74120   1.00000 ?