Ab Initio bulk free energy surface of proper ferroelectrics
arXiv:2205.11839 · doi:10.1103/bpz5-2pyw
Abstract
We report a systematic and accurate approach for deriving the bulk free energy surface (FES), a function of temperature, polarization, and strain, from the first-principles density functional theory (DFT) of proper ferroelectrics. The core of our approach is the metadynamics algorithm that extracts the polarization dependence of the FES from all-atom molecular dynamics simulations without an a priori ansatz. The rest of the FES is derived from the metadynamics trajectories that span the relevant phase space. We demonstrate our approach in the case of lead titanate. The errors across the phase transition, due to DFT numerics, all-atom molecular dynamics, and free energy evaluation by enhanced sampling, can be systematically controlled and are of the order of 1meV/atom. The accuracy of the resulting ab initio FES is only limited by the adopted functional approximation of DFT.
References in corpus (16)
- PLUMED 2: New feathers for an old bird
- Well-Tempered Metadynamics: A Smoothly Converging and Tunable Free-Energy Method
- Deep Potential Molecular Dynamics: a scalable model with the accuracy of quantum mechanics
- DeePMD-kit: A deep learning package for many-body potential energy representation and molecular dynamics
- DP-GEN: A concurrent learning platform for the generation of reliable deep learning based potential energy models
- DeePMD-kit v2: A software package for Deep Potential models
- Active Learning of Uniformly Accurate Inter-atomic Potentials for Materials Simulation
- A Variational Approach to Enhanced Sampling and Free Energy Calculations
- A Unified Approach to Enhanced Sampling
- Deep neural network for the dielectric response of insulators
- Devonshire-Landau free energy of BaTiO3 from first principles
- Phase-field modeling and electronic structural analysis of flexoelectric effect at 180° domain walls in ferroelectric PbTiO3
- Landau free energy of ferroelectric crystals by thermodynamic integration
- FerroX : A GPU-accelerated, 3D Phase-Field Simulation Framework for Modeling Ferroelectric Devices
- Thermal disorder and phonon softening in the ferroelectric phase transition of lead titanate
- Theory and phase-field simulations on electrical control of spin cycloids in a multiferroic