data_9659-ICSD
#©2013 by Fachinformationszentrum Karlsruhe, and the U.S. Secretary of 
#Commerce on behalf of the United States.  All rights reserved.
_database_code_ICSD                9659
_audit_creation_date               1986/08/12
_audit_update_record               2012/02/01
_chemical_name_systematic
;
Dicalcium Pentamagnesium Dihydroxide Catena-octasilicate
;
_chemical_formula_structural       'Ca2 Mg5 (O H)2 (Si8 O22)'
_chemical_formula_sum              'H2 Ca2 Mg5 O24 Si8'
_chemical_name_mineral             Tremolite
_publ_section_title
;
Crystal-chemical characterization of clinoamphiboles based on five 
new structure refinements
;
loop_
_citation_id
_citation_journal_abbrev
_citation_year
_citation_journal_volume
_citation_page_first
_citation_page_last
_citation_journal_id_ASTM
primary 'Mineralogical Society of America: Special Papers'
 1969 2 117 136 MSAPAX
_publ_author_name                  'Papike, J.J.;Ross, M.;Clark, J.R.'
_cell_length_a                     9.818(5)
_cell_length_b                     18.047(8)
_cell_length_c                     5.275(3)
_cell_angle_alpha                  90.
_cell_angle_beta                   104.65(5)
_cell_angle_gamma                  90.
_cell_volume                       904.27
_cell_formula_units_Z              2
_symmetry_space_group_name_H-M     'C 1 2/m 1'
_symmetry_Int_Tables_number        12
_refine_ls_R_factor_all            0.035
loop_
_symmetry_equiv_pos_site_id
_symmetry_equiv_pos_as_xyz
  1	'-x, y, -z'
  2	'-x, -y, -z'
  3	'x, -y, z'
  4	'x, y, z'
  5	'-x+1/2, y+1/2, -z'
  6	'-x+1/2, -y+1/2, -z'
  7	'x+1/2, -y+1/2, z'
  8	'x+1/2, y+1/2, z'
loop_
_atom_type_symbol
_atom_type_oxidation_number
Ca2+	2
H1+	1
Mg2+	2
O2-	-2
Si4+	4
loop_
_atom_site_label
_atom_site_type_symbol
_atom_site_symmetry_multiplicity
_atom_site_Wyckoff_symbol
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
_atom_site_occupancy
_atom_site_attached_hydrogens
_atom_site_B_iso_or_equiv
Ca1 Ca2+ 4 h 0 0.2776(1) 0.5 1. 0 0 
Mg1 Mg2+ 4 h 0 0.0878(1) 0.5 1. 0 0 
Mg2 Mg2+ 4 g 0 0.1766(1) 0 1. 0 0 
Mg3 Mg2+ 2 a 0 0 0 1. 0 0 
Si1 Si4+ 8 j 0.2804(1) 0.0840(1) 0.2964(1) 1. 0 0 
Si2 Si4+ 8 j 0.2887(1) 0.1711(1) 0.8042(1) 1. 0 0 
O1 O2- 8 j 0.1117(2) 0.0860(1) 0.2171(3) 1. 0 0 
O2 O2- 8 j 0.1185(2) 0.1712(1) 0.7240(3) 1. 0 0 
O3 O2- 4 i 0.1096(2) 0 0.7152(4) 1. 0 0 
O4 O2- 8 j 0.3654(2) 0.2480(1) 0.7933(3) 1. 0 0 
O5 O2- 8 j 0.3465(2) 0.1343(1) 0.0992(3) 1. 0 0 
O6 O2- 8 j 0.3436(2) 0.1185(1) 0.5884(3) 1. 0 0 
O7 O2- 4 i 0.3370(2) 0 0.2921(5) 1. 0 0 
H1 H1+ 4 i 0.199(7) 0 0.770(13) 1. 0 0.5 

#End of data_9659-ICSD


