Dynamic stabilization of cubic CaSi O3 perovskite at high temperatures and pressures from ab initio molecular dynamics

Tao Sun, Dong Bo Zhang, Renata M. Wentzcovitch

Research output: Contribution to journalArticle

35 Scopus citations

Abstract

The stability of cubic CaSiO3 perovskite (CaPv) at high temperatures and pressures is investigated by vibrational normal-mode analysis. We compute power spectra of mode autocorrelation functions using a recently developed hybrid approach combining ab initio molecular dynamics with lattice dynamics. These power spectra, together with the probability distributions of atomic displacements, indicate that cubic CaPv is stabilized at T∼600 K and P∼ 26 GPa. We then utilize the concept of phonon quasiparticles to characterize the vibrational properties of cubic CaPv at high temperature and obtain anharmonic phonon dispersions through the whole Brillouin zone. Such temperature-dependent phonon dispersions pave the way for more accurate calculations of free-energy, thermodynamic, and thermoelastic properties of cubic CaPv at Earth's lower mantle conditions.

Original languageEnglish (US)
Article number094109
JournalPhysical Review B - Condensed Matter and Materials Physics
Volume89
Issue number9
DOIs
StatePublished - Mar 26 2014

Fingerprint Dive into the research topics of 'Dynamic stabilization of cubic CaSi O3 perovskite at high temperatures and pressures from ab initio molecular dynamics'. Together they form a unique fingerprint.

  • Cite this