Molecular reaction dynamics is the study of elementary chemical processes and the tools used to probe, understand, and ultimately control them. It applies to both homogeneous and heterogeneous systems, including gas-phase reactions, solution chemistry, and surface processes—especially relevant for the exploration of elementary steps in catalysis. Today, advancing in chemistry requires a molecular-level understanding of reactivity.

Chemical kinetics, a classical discipline dating back to 1850, deals with reaction rates and how these are influenced by macroscopic variables such as concentration and temperature. The modern view, however, seeks to interpret these observations from a molecular and mechanistic perspective.

This school will cover the key aspects of chemical reaction kinetics and dynamics from a fundamental poinf of view, with a strong emphasis on theoretical and computational approaches, while also introducing some relevant experimental techniques. The proposal is framed within the area of computational simulations of chemical reactions, an area with a rich history in physical chemistry, encompassing both reactive and non-reactive processes.

One of the aims of the school is to provide a historical overview of the development of kinetics and dynamics, from their classical roots to modern computational techniques. This foundation will then lead to focused sessions on specific methodologies and case studies [1].

The program will cover various approaches to studying reaction kinetics [2] and dynamics, from classical to quantum methods [3], including cutting-edge techniques such as ring-polymer molecular dynamics and the application of artificial intelligence in this field. In addition, topics like the kinetics of heterogeneous catalysis and reactions in macromolecular systems will be addressed through kinetic Monte Carlo simulations [4] and hybrid QM/MM methodologies [5]. In particular, kinetic Monte Carlo allows bridging the vast gap in time and length scales between elementary molecular events and macroscopic kinetic behavior.

The school will combine theoretical lectures with hands-on computational sessions, offering participants the opportunity to directly apply the concepts learned to practical problems and, potentially, to their own research.

Several case studies have been selected to illustrate the methodologies presented. For instance, the reaction of an atom with a diatomic molecule will be used to explore quasi-classical trajectory (QCT) simulations and quantum dynamics approaches such as MCTDH and time-dependent real wave packet (TDRWP) methods[6]. For the kinetic Monte Carlo section, the mechanism of catalytic CO₂ hydrogenation on Ni(111) facets will be discussed in detail.

The school will consist of 8 theoretical lectures (2 hours each, total 16 hours) and 7 hands-on sessions organized in 8 slots (2 hours each, total 16 hours), held in a computer lab. These practical sessions will correspond to the theoretical concepts introduced in the lectures.

The planned lectures are the following:

1. Reaction Dynamics Perspective

2. Molecular Reaction Dynamics

3. Reaction Rate Theories

4. Automatic Methods for Reaction Mechanism Prediction

5. Kinetic Monte Carlo Simulations

6. Theoretical Study of the Mechanism and Kinetics of Enzyme Reactions

7. Calculating Kinetic Coefficients of Chemical Reactions Using Quantum Dynamics

8. Wave-Packet Quantum Dynamics: Overview and Applications to Chemical Reactions

References

[1] G. Czakó, T. Győri, D. Papp, V. Tajti, D. Tasi, J. Phys. Chem. A, 125, 2385–2393 (2021)

[2] D. González, A. Lema-Saavedra, S. Espinosa, E. Martínez-Núñez, A. Fernández-Ramos, A. Canosa, B. Ballesteros, E. Jiménez, Phys. Chem. Chem. Phys., 24, 23593–23601 (2022)

[3] R. Martínez, M. Paniagua, J. Mayneris-Perxachs, P. Gamallo, M. González, Phys. Chem. Chem. Phys., 19, 3857–3868 (2017)

[4] P. Lozano-Reis, H. Prats, R. Sayós, F. Illas, Journal of Catalysis, 425, 203–211 (2023)

[5] A. Camiruaga, I. Usabiaga, P. Pinillos, F. Basterretxea, J. Fernández, R. Martínez, J. Chem. Phys., 158 (2023)

[6] F. Esposito, P. Gamallo, M. González, C. Petrongolo, Phys. Chem. Chem. Phys., (2025) https://doi.org/10.1039/d5cp00539f