Deep-learning-based prediction of the tetragonal$\to$cubic transition in davemaoite

Abstract

Davemaoite, i.e., $CaSi{O}_3$ perovskite (CaPv), is the third most abundant phase in the lower mantle and exhibits a tetragonal-cubic phase transition at high pressures and temperatures. The phase boundary in CaPv has recently been proposed to be close to the cold slab adiabatic and cause mid-mantle seismic wave speed anomalies (Thomson et al., Nature 572, 643, 2019). In this study, we utilized accurate deep-learning-based simulations and thermodynamic integration techniques to compute free energies at temperatures ranging from 300 to 3,000 K and pressures up to 130 GPa. Our results indicate that CaPv exhibits a single cubic phase throughout lower-mantle conditions. This suggests that the phase diagram proposed by Thomson et al. requires revision, and mid-mantle seismic anomalies are likely attributable to other mechanisms.

References in corpus (13)

• ANI-1: An extensible neural network potential with DFT accuracy at force field computational cost
• A Spectral Analysis Method for Automated Generation of Quantum-Accurate Interatomic Potentials
• On-the-fly machine learning force field generation: Application to melting points
• How van der Waals interactions determine the unique properties of water
• The Phase Diagram of a Deep Potential Water Model
• Nonequilibrium free-energy calculation of solids using LAMMPS
• Oxygen fugacities of extrasolar rocks: Evidence for an Earth-like geochemistry of exoplanets
• Ab initio melting temperatures of bcc and hcp iron under the Earth's inner core condition
• A deep machine learning potential for atomistic simulation of Fe-Si-O systems under Earth's outer core conditions
• Modeling the High-Pressure Solid and Liquid Phases of Tin from Deep Potentials with ab initio Accuracy
• phq: a Fortran code to compute phonon quasiparticle properties and dispersions
• $\text{Ab initio}$ anharmonic thermodynamic properties of cubic CaSiO${}_3$ perovskite
• First-principles anharmonic vibrational study of the structure of calcium silicate perovskite under lower mantle conditions

Cited by in corpus (3)

• Melting Temperature of Iron Under the Earth's Inner Core Condition from Deep Machine Learning
• The Fe-Ni phase diagram and the Earth's inner core structure
• The thermodynamics of CaSiO3 in Earth's lower mantle