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RESEARCH PRODUCT
The pressure-induced ringwoodite to Mg-perovskite and periclase post-spinel phase transition: a Bader’s topological analysis of the ab initio electron densities
Filippo ParisiLuciana SciasciaFrancesco PrincivalleMarcello Merlisubject
Bader’s topological analysisElectron densityEquation of statePhase transitionRingwoodite Post-spinel phase transition Bader’s topological analysis Ab initio Catastrophe theory Critical pointsChemistryCatastrophe theoryAtoms in moleculesRingwooditeAb initioCritical pointsHartreeengineering.materialTopologyRingwoodite; Post-spinel phase transition; Bader’s topological analysis; Ab initio; Catastrophe theory; Critical pointsPost-spinel phase transitionRingwooditeGeochemistry and PetrologyBader’s topological analysiAb initioengineeringGeneral Materials SciencePerovskite (structure)description
In order to characterize the pressure-induced decomposition of ringwoodite (c-Mg2SiO4), the topological analysis of the electron density q(r), based upon the theory of atoms in molecules (AIM) developed by Bader in the framework of the catastrophe theory, has been performed. Calculations have been carried out by means of the ab initio CRYSTAL09 code at the HF/DFT level, using Hamiltonians based on the Becke- LYP scheme containing hybrid Hartree– Fock/density functional exchange–correlation terms. The equation of state at 0 K has been constructed for the three phases involved in the post-spinel phase transition (ringwoodite -> Mg-perovskite + periclase) occurring at the transition zone–lower mantel boundary. The topological results show that the decomposition of the ringwoodite at high pressures is caused by a conflict catastrophe. Furthermore, topological evidences of the central role played by the oxygen atoms to facilitate the pressure-induced ringwoodite decomposition and the subsequent phase transition have been noticed.
year | journal | country | edition | language |
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2011-11-01 |