2026-08-13 –, Room 2
NQCDynamics.jl is a platform for simulating chemical reaction dynamics of classical and mixed quantum-classical systems.
The package acts as a library of established dynamics methods and a playground to develop new ones, which can be applied to model Hamiltonians and high dimensional atomistic models. The modular structure enables the development of custom models and methods, as well as the capability to interface with machine learning potentials and the functionalities provided by ASE.
NQCDynamics.jl is a molecular dynamics package, primarily aimed at simulating condensed phase chemical reaction dynamics with a strong non-adiabatic character. Non-adiabaticity describes the regime where nuclear and electronic motion can no-longer be considered as separable i.e. beyond the Born-Oppenheimer approximation [^1,2]. Existing non-adiabatic mixed quantum-classical dynamics methods are mostly limited to systems with few electronic states[^3-6], and methods in development that target systems with higher complexity (e.g. more electronic states) are implemented in closed source codes.
The idea behind NQCDynamics.jl was to bridge the gap and provide a space for new methods to be trialled and improved by those in the non-adiabatic dynamics community; particularly those working on molecule-surface systems (which is an inherently non-adiabatic problem[^2,7]) such as ourselves in the Maurer Group. The package acts as a physics framework informed by advances made in non-adiabatic dynamics method development, which wraps around the DifferentialEquations.jl package that handles the dynamics propagation[^8]. It was first developed by in 2022 to benchmark new methods[^9-11] and simulate reactive scattering at surfaces[^12-16]. The package was recently refactored to include new functionality, improve maintainability, and increase efficiency and it is now release on the Julia General registry.
In my talk I will illustrate the code structure of NQCDynamics.jl, where it interfaces with other packages within the NQCD ecosystem to a run dynamics simulation, and the associated flexibility that this modular approach provides. I will give examples of the common mixed quantum-classical dynamics methods used for non-adiabatic surface dynamics, particularly the Independent Electron Surface Hopping approach, which has no other open source implementations.
To conclude, I will present the resources for assisting new users and introduce our “NQCRecipes” tutorial repository which contains more complex workflows explained in detail.
References:
[^1]: Ostlund, Neil. Modern Quantum Chemistry : Introduction to Advanced Electronic Structure Theory. January 1, 1982. https://www.academia.edu/65821991/Modern_quantum_chemistry_introduction_to_advanced_electronic_structure_theory.
[^2]: Dou, Wenjie, and Joseph E. Subotnik. “Nonadiabatic Molecular Dynamics at Metal Surfaces.” The Journal of Physical Chemistry A 124, no. 5 (2020): 757–71. https://doi.org/10.1021/acs.jpca.9b10698.
[^3]: Tully, John C. “Molecular Dynamics with Electronic Transitions.” The Journal of Chemical Physics 93, no. 2 (1990): 1061–71. https://doi.org/10.1063/1.459170.
[^4]: Tully, John C. “Mixed Quantum–Classical Dynamics.” Faraday Discussions 110, no. 0 (1998): 407–19.
[^5]: Crespo-Otero, Rachel, and Mario Barbatti. “Recent Advances and Perspectives on Nonadiabatic Mixed Quantum–Classical Dynamics.” Chemical Reviews 118, no. 15 (2018): 7026–68.
[^6]: Agostini, Federica, and Basile F. E. Curchod. “Different Flavors of Nonadiabatic Molecular Dynamics.” WIREs Computational Molecular Science 9, no. 5 (2019): e1417. https://doi.org/10.1002/wcms.1417.
[^7]: Nienhaus, H., H. S. Bergh, B. Gergen, A. Majumdar, W. H. Weinberg, and E. W. McFarland. “Electron-Hole Pair Creation at Ag and Cu Surfaces by Adsorption of Atomic Hydrogen and Deuterium.” Physical Review Letters 82, no. 2 (1999): 446–49. https://doi.org/10.1103/PhysRevLett.82.446.
[^8]: Rackauckas, Christopher, and Qing Nie. “DifferentialEquations.Jl – A Performant and Feature-Rich Ecosystem for Solving Differential Equations in Julia.” Journal of Open Research Software 5, no. 1 (2017). https://doi.org/10.5334/jors.151.
[^9]: Gardner, James, Oscar A. Douglas-Gallardo, Wojciech G. Stark, et al. “NQCDynamics.Jl: A Julia Package for Nonadiabatic Quantum Classical Molecular Dynamics in the Condensed Phase.” The Journal of Chemical Physics 156, no. 17 (2022): 174801. https://doi.org/10.1063/5.0089436.
[^10]: Gardner, James, Scott Habershon, and Reinhard J. Maurer. 2023. “Assessing Mixed Quantum-Classical Molecular Dynamics Methods for Nonadiabatic Dynamics of Molecules on Metal Surfaces.” The Journal of Physical Chemistry C 127 (31): 15257–70. https://doi.org/10.1021/acs.jpcc.3c03591.
[^11]: Gardner, James, Daniel Corken, Svenja M. Janke, Scott Habershon, and Reinhard J. Maurer. “Efficient Implementation and Performance Analysis of the Independent Electron Surface Hopping Method for Dynamics at Metal Surfaces.” The Journal of Chemical Physics 158, no. 6 (2023): 064101. https://doi.org/10.1063/5.0137137
[^12]: Stark, Wojciech G., Julia Westermayr, Oscar A. Douglas-Gallardo, James Gardner, Scott Habershon, and Reinhard J. Maurer. “Machine Learning Interatomic Potentials for Reactive Hydrogen Dynamics at Metal Surfaces Based on Iterative Refinement of Reaction Probabilities.” The Journal of Physical Chemistry C 127, no. 50 (2023): 24168–82. https://doi.org/10.1021/acs.jpcc.3c06648.
[^13]: Box, Connor L., Nils Hertl, Wojciech G. Stark, and Reinhard J. Maurer. “Room Temperature Hydrogen Atom Scattering Experiments Are Not a Sufficient Benchmark to Validate Electronic Friction Theory.” The Journal of Physical Chemistry Letters 15, no. 51 (2024): 12520–25. https://doi.org/10.1021/acs.jpclett.4c02468.
[^14]: Stark, Wojciech G., Connor L. Box, Matthias Sachs, Nils Hertl, and Reinhard J. Maurer. “Nonadiabatic Reactive Scattering of Hydrogen on Different Surface Facets of Copper.” Physical Review B 112, no. 3 (2025): 035422. https://doi.org/10.1103/h7vd-94pk.
[^15]: Hong, Junyang, Nils Hertl, Reinhard J. Maurer, Gang Meng, and Bin Jiang. “Vibrational Excitation in Gas-Surface Collisions of CO with Au(111): A First-Principles Nonadiabatic Dynamics Study.” The Journal of Physical Chemistry C 129, no. 6 (2025): 2944–52. https://doi.org/10.1021/acs.jpcc.4c06618.
[^16]: Lu, Xuexun, Nils Hertl, Sara Oregioni, et al. “A Haldane–Anderson Hamiltonian Model for Hyperthermal Hydrogen Scattering from a Semiconductor Surface.” The Journal of Chemical Physics 164, no. 2 (2026): 024707. https://doi.org/10.1063/5.0297254.
I am a second year Chemistry PhD student and the University of Warwick, researching light driven molecular dynamics of molecule-metal surface systems.