data_CaSi2O5triclinic
# 1. Publication data

_journal_name_full              'Nature'
_journal_year                   1996
_journal_volume                 384
_journal_page_first             441
_journal_paper_doi              10.1038/384441a0
_audit_creation_date            2016-10-13
_audit_creation_method          'From publication'
_audit_contact_author_name	'R.J. Angel'
_audit_contact_author_email	rossjohnangel@gmail.com

# 2. Chemical data
_chemical_formula_sum                    'Ca Si2 O5'
_chemical_formula_weight                 176.25
_chemical_compound_source                
;
synthesised at 11 GPa and 1,350 C for 4 hours
;

# 3. Unit cell
_cell_formula_units_Z                    8
_cell_length_a                           12.9170(2)
_cell_length_b                           8.4504(1)
_cell_length_c                           6.5150(1)
_cell_angle_alpha                        93.161(1)
_cell_angle_beta                         111.475(1)
_cell_angle_gamma                        90.793(1)
_cell_volume                             660.32(2)
_cell_measurement_temperature            298
_cell_measurement_pressure               100



# 4. experimental details
_diffrn_ambient_temperature              298
_diffrn_ambient_pressure                 100
_diffrn_radiation_probe                  X-ray
_diffrn_radiation_type                   'Mo K\a'
_diffrn_radiation_wavelength             0.71073
_diffrn_measurement_device               '4-circle goniometer'
_diffrn_measurement_device_type          'Enraf-Nonius CAD4'


# 5. Symmetry information
_space_group_crystal_system              triclinic
_space_group_name_H-M_alt		'I -1'
_refine_special_details
;
 Non-conventional cell and space group setting chosen to reflect
relationship to conventional setting of monoclinic aristotype phase
;

loop_
 _symmetry_equiv_pos_as_xyz
x,y,z
-x,-y,-z
x+1/2,y+1/2,z+1/2
x-1/2,y-1/2,z-1/2

# 6. Structural data
loop_
 _atom_site_label
 _atom_site_type_symbol
 _atom_site_fract_x
 _atom_site_fract_y
 _atom_site_fract_z
 _atom_site_adp_type
 _atom_site_U_iso_or_equiv
 _atom_site_occupancy

Ao       Ca 0.11140(7) 0.43088(9)  0.29330(13) Biso 1.011  1.0
Ax       Ca 0.62141(7) 0.40746(10) 0.23243(13) Biso 1.117  1.0
Moo      Si 0.25       0.25        0.75        Biso 0.871  1.0
Mox      Si 0.75       0.25        0.75        Biso 0.859  1.0 
Ma       Si 0.01253(9) 0.23431(13) 0.81327(18) Biso 0.885  1.0
Too      Si 0.36576(9) 0.43601(13) 0.24022(18) Biso 0.863  1.0
Tox      Si 0.86854(9) 0.44784(13) 0.20955(18) Biso 0.868  1.0
O1o      O  0.38070(22) 0.31432(32) 0.76147(46) Biso 0.982  1.0
O1x      O  0.88533(22) 0.30383(32) 0.76990(46) Biso 0.972  1.0
O2oo     O  0.44905(22) 0.32661(33) 0.42631(45) Biso 1.002  1.0
O2ox     O  0.95575(23) 0.34501(33) 0.38484(48) Biso 1.113  1.0
O2ao     O  0.20752(22) 0.19205(33) 0.45295(45) Biso 0.964  1.0
O2ax     O  0.71991(23) 0.17949(33) 0.47000(47) Biso 1.047  1.0
O3oo     O  0.20522(22) 0.44617(31) 0.67947(46) Biso 0.967  1.0
O3ox     O  0.70633(22) 0.44986(32) 0.65457(48) Biso 1.007  1.0
O3ao     O  0.43388(22) 0.06725(47) 0.60661(47) Biso 0.983  1.0
O3ax     O  0.94845(21) 0.04715(31) 0.66552(45) Biso 0.871  1.0