Ab Initio bulk free energy surface of proper ferroelectrics
Fuente:
arXiv
Saved in:
| Main Authors: | , , , , , |
|---|---|
| Format: | Preprint |
| Published: |
2022
|
| Subjects: | |
| Online Access: | |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1866912888823742464 |
|---|---|
| author | Xie, Pinchen Chen, Yixiao Xu, Xinyu Yao, Zhi E, Weinan Car, Roberto |
| author_facet | Xie, Pinchen Chen, Yixiao Xu, Xinyu Yao, Zhi E, Weinan Car, Roberto |
| contents | 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. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2205_11839 |
| institution | arXiv |
| publishDate | 2022 |
| record_format | arxiv |
| spellingShingle | Ab Initio bulk free energy surface of proper ferroelectrics Xie, Pinchen Chen, Yixiao Xu, Xinyu Yao, Zhi E, Weinan Car, Roberto Materials Science 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. |
| title | Ab Initio bulk free energy surface of proper ferroelectrics |
| topic | Materials Science |
| url | https://arxiv.org/abs/2205.11839 |