Machine Learning for Observables: Reactant to Product State Distributions for Atom-Diatom Collisions

Autor: Arnold, Julian, Koner, Debasish, Käser, Silvan, Singh, Narendra, Bemish, Raymond J., Meuwly, Markus
Rok vydání: 2020
Předmět:
Zdroj: J. Phys. Chem. A 2020, 124, 35, 7177-7190
Druh dokumentu: Working Paper
DOI: 10.1021/acs.jpca.0c05173
Popis: Machine learning-based models to predict product state distributions from a distribution of reactant conditions for atom-diatom collisions are presented and quantitatively tested. The models are based on function-, kernel- and grid-based representations of the reactant and product state distributions. While all three methods predict final state distributions from explicit quasi-classical trajectory simulations with R$^2$ > 0.998, the grid-based approach performs best. Although a function-based approach is found to be more than two times better in computational performance, the kernel- and grid-based approaches are preferred in terms of prediction accuracy, practicability and generality. The function-based approach also suffers from lacking a general set of model functions. Applications of the grid-based approach to nonequilibrium, multi-temperature initial state distributions are presented, a situation common to energy distributions in hypersonic flows. The role of such models in Direct Simulation Monte Carlo and computational fluid dynamics simulations is also discussed.
Databáze: arXiv