Lecture by Prof. Roman Martoňák

IEE SAS invite you to a lecture by Prof. Roman Martoňák (FMFI UK).
Febr. 12, 2025, 10,00 a.m., in IEE SAS meeting room 101.

Simulations of Structural Phase Transitions in Crystals Using Metadynamics

Abstract:
Structural phase transitions in crystals induced by pressure or temperature are complex phenomena of great importance. Besides fundamental interest e.g. in Earth and planetary science, they also allow us to prepare new materials with unique properties. Most of them are reconstructive, thermodynamically first order, and involve breaking and creation of chemical bonds. In past two decades a great progress was achieved in prediction of crystal structures, but a reliable prediction of structural transformations still lags much behind. The main problem is kinetics which ultimately decides about the outcome of the transformation. Understanding kinetics requires a detailed information about free-energy barriers involved in the microscopic transformation pathways. An important ingredient is also nucleation whose understanding in solid-solid transitions is still very incomplete. One of effective approaches to study these phenomena is metadynamics (Laio and Parrinello 2002; Martonak, Laio and Parrinello 2003). Another important ingredient are machine-learning based potentials which nowadays allow to simulate 10^5 or more atoms with high accuracy. In the talk I will present the progress made during past 20 years, illustrate the main achievements and outline possible future directions.