Neural-network based simulation of rare event processes at the water/oxide interface
Subproject P12
Atomistic computer simulations of processes occurring at the water/oxide interface are challenging in several ways. The calculation of atomic forces based on ab initio methods is computationally very demanding, and barrier crossing events may lead to long computation times. Both these aspects severely limit accessible system sizes and simulation times.
Building on the neural network potentials and the rare events simulation methods developed in the first funding period, project P12 will simulate complex dynamical processes occurring at the oxide/water interface. In particular, one central objective will be to investigate heterogeneous ice nucleation on various mineral surfaces that are of atmospheric significance. The studies will involve tight interactions with projects P03 Kresse and P02 Diebold. In addition, project P12 will continue to explore the use of machine learning approaches for trajectory-based rare events sampling. Here, the main objectives are to develop efficient latent space methods to sample path distributions and the on-the-fly optimization of transition path sampling simulations based on information encoded in learned committor functions.
Expertise
Our research efforts focus on the development of simulation algorithms and their application to investigate dynamical processes in condensed matter systems based on the principles of equilibrium and non-equilibrium statistical mechanics. In particular, we have helped to create the transition path sampling methodology for the simulation of rare but important events, such as nucleation aprocesses, chemical reactions and biomolecular reorganizations. More recently, we have worked on applying machine learning methods to molecular structure recognition and the representation of potential and free energy surfaces.
Recent research topics include:
- Self-assembly of nanocrystals
- Folding and unfolding of biopolymers
- Interfaces in aqueous systems
- Phase separation in alloys
- Thermo-polarisation
- Structure and dynamics of water and ice
- Cavitation
- Crystallization
- Non-equilibrium work fluctuations
Team
Associates
Publications
2022

Tröster, Andreas; Verdi, Carla; Dellago, Christoph; Rychetsky, Ivan; Kresse, Georg; Schranz, Wilfried
Hard antiphase domain boundaries in strontium titanate unravelled using machine-learned force fields
Journal ArticleIn: Physical Review Materials, vol. 6, no. 9, pp. 094408, 2022.
Abstract | Links | BibTeX | Tags: P03, P12
@article{Troester2022,
title = {Hard antiphase domain boundaries in strontium titanate unravelled using machine-learned force fields},
author = {Andreas Tröster and Carla Verdi and Christoph Dellago and Ivan Rychetsky and Georg Kresse and Wilfried Schranz},
doi = {10.1103/physrevmaterials.6.094408},
year = {2022},
date = {2022-09-16},
urldate = {2022-09-16},
journal = {Physical Review Materials},
volume = {6},
number = {9},
pages = {094408},
publisher = {American Physical Society (APS)},
abstract = {We investigate the properties of hard antiphase boundaries in SrTiO_{3} using machine-learned force fields. In contrast to earlier findings based on standard \textit{ab initio} methods, for all pressures up to 120kbar the observed domain wall pattern maintains an almost perfect Néel character in quantitative agreement with Landau-Ginzburg-Devonshire theory, and the in-plane polarization P_{3} shows no tendency to decay to zero. Together with the switching properties of P_{3} under reversal of the Néel order parameter component, this provides hard evidence for the presence of rotopolar couplings. The present approach overcomes the severe limitations of \textit{ab initio} simulations of wide domain walls and opens avenues toward concise atomistic predictions of domain-wall properties even at finite temperatures.},
keywords = {P03, P12},
pubstate = {published},
tppubtype = {article}
}
