Walker, AM;
Tyer, RP;
Bruin, RP;
Dove, MT;
(2008)
The compressibility and high pressure structure of diopside from first principles simulation.
PHYS CHEM MINER
, 35
(7)
359 - 366.
10.1007/s00269-008-0229-3.
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PDF
Diopside_PCM.pdf Available under License : See the attached licence file. Download (193kB) |
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Text (Diopside results)
diopside_results.cif.txt Available under License : See the attached licence file. Download (63kB) |
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PDF (Supporting information)
supinfo.pdf Available under License : See the attached licence file. Download (133kB) |
Abstract
The structure of diopside (CaMgSi2O6) has been calculated at pressures between 0 and 25 GPa using the planewaves and pseudopotentials approach to density functional theory. After applying a pressure correction of 4.66 GPa to allow for the under-binding usually associated with the generalized gradient approximation, cell parameters are in good agreement with experiment. Fitting to the third-order Birch-Murnaghan equation of state yields values of 122 GPa and 4.7 for the bulk modulus and its pressure derivative. In addition to cell parameters, our calculations provide all atomic positional parameters to pressures considerably beyond those currently available from experiment. We have analyzed these data in terms of polyhedral rigidity and regularity and find that the most compressible Ca polyhedron becomes markedly less anisotropic above 10 GPa.
Type: | Article |
---|---|
Title: | The compressibility and high pressure structure of diopside from first principles simulation |
Open access status: | An open access version is available from UCL Discovery |
DOI: | 10.1007/s00269-008-0229-3 |
Keywords: | diopside, density functional theory, equation of state, pyroxene, compression, CRYSTAL-STRUCTURE, PYROXENES, DISTORTION |
UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences |
URI: | https://discovery-pp.ucl.ac.uk/id/eprint/19412 |
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