From growth to scattering: Decoding nanoparticle shape

Michael Engel, Friedrich-Alexander-Universität Erlangen-Nürnberg, Germany

Nanoparticle shape emerges from atomic-scale growth processes and strongly influences the properties and organization of particle-based materials. Yet morphology is typically accessed only indirectly through ensemble-averaged measurements, making it challenging to connect observed particle shapes to the mechanisms by which they form.
In this talk, I will discuss two complementary computational approaches to this problem. Kinetic Monte Carlo simulations provide access to the forward problem of shape formation, revealing how local growth kinetics and surface processes give rise to characteristic nanoparticle morphologies. Scattering calculations provide a complementary connection to experiment by predicting diffraction and total scattering directly from structural models. Efficient Debye-based methods enable such calculations for large nanoparticle systems, while differentiable scattering extends them to the inverse problem, allowing particle morphology to be optimized directly against experimental data.
Using simulated and experimental examples, I will show how these approaches can be used to understand the emergence of particle shape and to reconstruct three-dimensional morphology from scattering profiles, including habits, truncations, and deviations from idealized geometries. Together, they connect growth mechanisms, particle structure, and experimental observables, and provide a basis for more quantitative studies of nanoparticle formation and morphology.