Critical Assessment of Classical Potentials for MgSiO₃ Perovskite with Application to Thermal Conductivity Calculations

Abstract

Atomistic simulations using classical empirical potentials are an invaluable tool for studying minerals in lower-mantle conditions. Here we systematically survey literature potentials for MgSiO3 perovskite. The value of the present work is two-fold: (i) a systematic data set for a large number of potentials is determined, reproducing previous results where they exist and filling in gaps where they do not, and (ii) the first predictions using these potentials for the thermal-transport properties critical to geothermal models is provided. We focus particularly on the thermal expansion and the thermal-transport properties, both of which probe the anharmonic structure of the potential. Simple two-body potentials with the partially-ionic charges are found to be the most successful representation of MgSiO3 perovskite properties. The addition of a shell model or many-body interactions does not lead to any systematic improvement.

Department(s)

Physics

Keywords and Phrases

Anharmonic; Atomistic simulations; Boltzmann transport equation; Critical assessment; Data sets; Empirical potentials; Filling in; Magnesium silicates; Many-body interactions; Shell models; Magnesium; Perovskite; Silicates; Transport properties; Magnesium; Perovskite; Silicates; Transport properties; experimental mineralogy; geothermometry; heat source; heat transfer; lower mantle; numerical model; perovskite; thermal conductivity; thermal expansion; thermal structure

International Standard Serial Number (ISSN)

0031-9201

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2012 Elsevier, All rights reserved.

Publication Date

01 Nov 2012

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