data_global
_chemical_name_mineral 'Melilite'
loop_
_publ_author_name
'Armbruster T'
'Rothlisberger F'
'Seifert F'
_journal_name_full 'American Mineralogist'
_journal_volume 75 
_journal_year 1990
_journal_page_first 847
_journal_page_last 858
_publ_section_title
;
 Layer topology, stacking variation and site distortion in melilite-related
 compounds in the system CaO-ZnO-GeO2-SiO2
 high-temperature polymorph
 Ca2ZnGe2O7
;
_database_code_amcsd 0001314
_chemical_formula_sum 'Ca2 Zn Ge2 O7'
_cell_length_a 7.950
_cell_length_b 7.950
_cell_length_c 5.186
_cell_angle_alpha 90
_cell_angle_beta 90
_cell_angle_gamma 90
_cell_volume 327.768
_exptl_crystal_density_diffrn      4.081
_symmetry_space_group_name_H-M 'P -4 21 m'
loop_
_space_group_symop_operation_xyz
  'x,y,z'
  '1/2-y,1/2-x,z'
  'y,-x,-z'
  '1/2-x,1/2+y,-z'
  '-x,-y,z'
  '1/2+y,1/2+x,z'
  '-y,x,-z'
  '1/2+x,1/2-y,-z'
loop_
_atom_site_label
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
CaX   0.33200   0.16800   0.50380
Zn1   0.00000   0.00000   0.00000
Ge2   0.14206   0.35794   0.95310
O1   0.50000   0.00000   0.18100
O2   0.14000   0.36000   0.27700
O3   0.08800   0.17900   0.78300
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
CaX 0.04900 0.04900 0.01410 0.03800 0.00010 -0.00010
Zn1 0.01960 0.01960 0.00920 0.00000 0.00000 0.00000
Ge2 0.01520 0.01520 0.01090 0.00020 0.00400 -0.00400
O1 0.11000 0.11000 0.00600 -0.09000 0.00000 0.00000
O2 0.04200 0.04200 0.01200 0.02500 -0.00200 0.00200
O3 0.20000 0.04200 0.03100 -0.07500 0.06100 -0.02600