Inorganic Solid Phases

omphacite (Na0.55Ca0.45Mg0.45Al0.55Si2O6) Crystal Structure

General Information

  • Phase Label(s): Na0.55Ca0.45Mg0.45Al0.55Si2O6
  • Structure Class(es):
  • Classification by Properties:
  • Mineral Name(s): omphacite
  • Pearson Symbol: mP40
  • Space Group: 13
  • Phase Prototype: (Na0.5Ca0.5)(Mg0.4Fe0.2Al0.4)Si2O6
  • Measurement Detail(s): automatic diffractometer; 12 (determination of cell parameters), automatic diffractometer; Rigaku RASA-IIS (determination of structural parameters), X-rays, Mo Kα (determination of cell and structural parameters)
  • Phase Class(es):
  • Compound Class(es): silicate
  • Interpretation Detail(s): complete structure determined, least-squares refinement, R = 0.0515
  • Sample Detail(s): omphacite sample from China, Shangdong Province, Zhucheng County, single crystal (determination of cell parameters), single crystal, 0.25×0.32×0.6 mm3 (determination of structural parameters)

Substance Summary

  • Standard Formula: NaCaMgAlSi4O12
  • Alphabetic Formula: AlCaMgNaO12Si4
  • Published Formula: omphacite
  • Refined Formula: AlCa0.93MgNaO12Si3.99
  • Wyckoff Sequence: 7,a20
  • Z Formula Units: 2
  • Density: ρ = 3.28 Mg·m−3

Crystallographic Data

Cell Parameters

Published Data
Standardized Data
Unit Cell
Niggli-Reduced Cell
Space Group
a
b
c
α
β
γ
a/b
b/c
c/a
V

Atom Coordinates

Standardized

Site
Element
Wyckoff Symbol
Symmetry
X
Y
Z
Occupation
Co-ord. No.
Atomic Env.

Published

Site
Element
Wyckoff Symbol
Symmetry
X
Y
Z
Occupation

Displacement Parameters

Anisotropic

Site
β11 [nm2]
β22 [nm2]
β33 [nm2]
β12 [nm2]
β13 [nm2]
β23 [nm2]

Experimental Details

Reference

3D Interactive Structure

About this content

  • Database name

    PAULING FILE Multinaries Edition – 2012

  • Dataset ID

    sd_1214318

  • Copyright

    ©Springer & Material Phases Data System (MPDS), Switzerland & National Institute for Materials Science (NIMS), Japan, 2016

  • Chief Editor

    Pierre Villars, Material Phases Data System (MPDS), CH-6354 Vitznau, Switzerland

    villars.mpds@bluewin.ch

  • Credits

    SpringerMaterials Release 2016.

    Data generated pre-2002: © Springer & MPDS & NIMS; post-2001: © Springer & MPDS

    All Rights Reserved. Version 2016.10.

    Project Coordinator: Shuichi Iwata

    Section-Editor: Karin Cenzual (Crystal Structures)

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