Ab initio structural optimization at finite temperatures based on anharmonic phonon theory: Application to the structural phase transitions of BaTiO${}_3$

Abstract

We formulate a first-principle scheme for structural optimization at finite temperature ($T$) based on the self-consistent phonon (SCP) theory, which accurately takes into account the effect of strong phonon anharmonicity. The $T$-dependence of the shape of the unit cell and internal atomic configuration is determined by minimizing the variational free energy in the SCP theory. At each optimization step, the interatomic force constants in the new structure are calculated without running additional electronic structure calculations, which makes the method dramatically efficient. We demonstrate that the thermal expansion of silicon and the three-step structural phase transitions in BaTiO${}_3$ and its pressure-temperature ($p$-$T$) phase diagram are successfully reproduced. The present formalism will open the way to the non-empirical prediction of physical properties at finite $T$ of materials having a complex structural phase diagram.

References in corpus (19)

• Quantum ESPRESSO: a modular and open-source software project for quantum simulations of materials
• Restoring the density-gradient expansion for exchange in solids and surfaces
• Generalized gradient approximation for solids and their surfaces
• Advanced capabilities for materials modelling with Quantum ESPRESSO
• Fermi surface nesting and the origin of Charge Density Waves in metals
• On-the-fly machine learning force field generation: Application to melting points
• Entropy driven stabilization of energetically unstable crystal structures explained from first principles theory
• The Stochastic Self-Consistent Harmonic Approximation: Calculating Vibrational Properties of Materials with Full Quantum and Anharmonic Effects
• First-Principles Lattice Dynamics Method for Strongly Anharmonic Crystals
• Anharmonic phonon spectra of PbTe and SnTe in the self-consistent harmonic approximation
• Anharmonic and Quantum Fluctuations in Molecular Crystals: A First-Principles Study of the Stability of Paracetamol
• Critical enhancement of thermopower in a chemically tuned polar semimetal MoTe${}_2$
• Thermodynamics and dielectric response of ${\text{BaTiO}}_3$ by data-driven modeling
• Weak Dimensionality Dependence and Dominant Role of Ionic Fluctuations in the Charge-Density-Wave Transition of NbSe${}_2$
• Quantum Self-Consistent Ab-Initio Lattice Dynamics
• Anharmonic Grüneisen theory based on self-consistent phonon theory: Impact of phonon-phonon interaction neglected in the quasiharmonic theory
• Anharmonic theory of superconductivity in the high-pressure materials
• Superconducting dome in ferroelectric-type materials from soft mode instability
• Giant enhancement of cryogenic thermopower by polar structural instability in the pressurized semimetal MoTe2

Cited by in corpus (6)

• Full optimization of quasiharmonic free energy with anharmonic lattice model: Application to thermal expansion and pyroelectricity of wurtzite GaN and ZnO
• Anharmonic phonon behavior via irreducible derivatives: self-consistent perturbation theory and molecular dynamics
• Beyond Gaussian fluctuations of quantum anharmonic nuclei
• High-throughput calculations of antiferromagnets hosting anomalous transport phenomena
• Approximations in first-principles volumetric thermal expansion determination
• Efficient first-principles approach to Gibbs free energy with thermal expansion