View Item 

Activity-composition relations in the system CaCO3-MgCO3 predicted from static structure energy calculations and Monte Carlo simulations

Access Status
Open access
Authors
Vinograd, V.
Burton, B.
Gale, Julian
Allan, N.
Winkler, B.
Date
2006
Type
Journal Article

Metadata
Show full item record
Citation
Vinograd, V and Burton, Benjamin and Gale, Julian and Allan, Neil and Winkler, B. 2006. Activity-composition relations in the system CaCO3-MgCO3 predicted from static structure energy calculations and Monte Carlo simulations. Geochimica et Cosmochimica Acta 71 (4): 974-983.
Source Title
Geochimica et Cosmochimica Acta
DOI
Faculty
Department of Applied Chemistry
Division of Engineering, Science and Computing
Faculty of Science
Remarks

NOTICE: this is the author’s version of a work that was accepted for publication in Geochimica et Cosmochimica Acta. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Geochimica et Cosmochimica Acta, Vol. 71, No. 4 (2006). DOI: 10.1016/j.gca.2006.11.008

URI
Collection
Abstract

Thermodynamic mixing properties and subsolidus phase relations of the rhombohedral carbonate system, (1 - x) CaCO3 - x MgCO3, were modelled in the temperature range of 623-2023 K with static structure energy calculations based on well-parameterised empirical interatomic potentials. Relaxed static structure energies of a large set of randomly varied structures in a 4 x 4 x 1 supercell of R3c calcite (a = 19.952A , c = 17.061A ) were calculated with the General Utility Lattice Program (GULP). These energies were cluster expanded in a basis set of 12 pair-wise effective interactions. Temperature-dependent enthalpies of mixing were calculated by the Monte Carlo method. Free energies of mixing were obtained by thermodynamic integration of the Monte Carlo results. The calculated phase diagram is in good agreement with experimental phase boundaries.