- Machine learning and Physical Chemistry. Prediction of dynamical properties of quantum materials using neural networks: Diffusion, spectroscopy and reaction rates.
- Developing new methods to describe quantum effects in classical simulations: Path integral molecular dynamics for indistinguishable particles.
- Simulations of chemical processes on water surfaces with applications to atmospheric chemistry and hydrogen storage in clathrate hydrates.
Our research follows two main directions: 1. Developing simulation methods for describing chemical and physical phenomena that are inadequately described using available models. 2. Applying these new tools and others to solve fascinating problems at the interface of chemistry and physics.
The main tool is molecular dynamics (MD) simulations, a “virtual microscope” that allows following the classical dynamics of individual atoms in time and investigating chemical and physical processes for large systems (liquids and solids). However, MD simulation are inapplicable at low temperatures or for quantum materials, whose properties are determined from the quantum correlations between their constituent particles. Unfortunately, solving the quantum equations of motion is impossible for large systems.
To overcome this important problem, we develop path Integral MD simulations (PIMD) which allow describing the thermodynamic properties of quantum condensed phase systems while being computationally efficient. We aim to solve two limitations of PIMD simulations that will greatly extend their applicability:
- Using neural networks to obtain dynamical properties of quantum systems e.g., diffusivity, reaction rates and spectroscopy. We will apply this approach to hydrogen storage in ice-like cages (clathrate hydrates), promising renewable energy materials. Since hydrogen is the lightest element and since clathrate hydrates are formed at low temperatures, quantum effects cannot be neglected.
- PIMD simulations for bosons and fermions. This development would allow applications to systems of ultracold trapped atoms which exhibit fascinating phenomena, such as Bose-Einstein condensation, and can potentially be used in emerging quantum technologies.