Crystal chemistry of forsterite; a first-principles study

Abstract

Other| August 01, 1997 Crystal chemistry of forsterite; a first-principles study Renata M. Wentzcovitch; Renata M. Wentzcovitch University of Minnesota, Department of Chemical Engineering and Materials Sciences, Minneapolis, MN, United States Search for other works by this author on: GSW Google Scholar Lars Stixrude Lars Stixrude Georgia Institute of Technology, United States Search for other works by this author on: GSW Google Scholar American Mineralogist (1997) 82 (7-8): 663–671. https://doi.org/10.2138/am-1997-7-802 Article history first online: 02 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Twitter LinkedIn Tools Icon Tools Get Permissions Search Site Citation Renata M. Wentzcovitch, Lars Stixrude; Crystal chemistry of forsterite; a first-principles study. American Mineralogist 1997;; 82 (7-8): 663–671. doi: https://doi.org/10.2138/am-1997-7-802 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyAmerican Mineralogist Search Advanced Search Abstract We present a first-principles study (local density approximation) of the structural properties of forsterite under pressure. This highly anisotropic magnesium orthosilicate is the most abundant phase of the Earth’s upper mantle, and its elastic properties determine the rheology of this region. We perform full structural optimizations and investigate its compressive behavior up to 25 GPa. We obtain a pressure dependence of lattice parameters that agrees well with experiments to 17.2 GPa. We predict that the coordination polyhedra compress essentially isotropically, and we explain the anisotropy of forsterite in terms of the nonuniform distribution of coordination polyhedra having different but nearly uniform compressibilities. In agreement with Brodholt et al. (1996), we do not find theoretical evidence for sudden changes in compression mechanisms in this mineral as had been suggested from experiments. Our results support the hypothesis that such compressive anomalies are caused by solidification of the pressure medium. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.