Working Group 1

Deliverable 1. Creation of new protocols for excited state calculations (M12); Results of test calculations for ground- and excited-states of confined systems (M24); Creation of diverse datasets (M36); Assessment of methods against created datasets (M48).

As scheduled, new protocols for excited state calculations have been created and results for ground- and excited-states of confined systems have been delivered (see, e.g., https://doi.org/10.1002/cphc.202300317). A new method for calculating the interaction of atoms/molecules/clusters and their supports has been proposed and tested against CCSD(T)-based benchmarking (see, e.g., https://doi.org/10.1039/D4RA05401F), having extended it to excited states and cluster-support systems featuring Jahn-Teller distortions and conical intersections (see, e.g., https://doi.org/10.1039/D4CP03271C). Diverse datasets are being created (https://cost-cosy.eu/databases).

1.1. Creation of new protocols for excited state calculations (M12).

Delivered – As scheduled, the work on the first sub-deliverable has been completed.

Scientific publications proving the achievement of the deliverable are:

1. Mitrushchenkov, A. O.; de Lara‐Castells, M. P. High‐level Ab Initio Evidence of Bipyramidal Cu5 Clusters as Fluxional Jahn‐Teller Molecules. ChemPhysChem, 2023, 24. https://doi.org/10.1002/cphc.202300317. Front cover – https://doi.org/10.1002/cphc.202300638.

2. Krupka, K. M.; de Lara-Castells, M. P. Support Effects on Conical Intersections of Jahn-Teller Fluxional Metal Clusters on the Sub-Nanoscale. Physical Chemistry Chemical Physics, 2024. https://doi.org/10.1039/d4cp03271c.

3. Krzemińska A.; Biczysko M.; Pernal K; Hapka M. Anisole–Water and Anisole–Ammonia Complexes in Ground and Excited (S1) States: A Multiconfigurational Symmetry-Adapted Perturbation Theory (SAPT) Study. The Journal of Physical Chemistry A, 2024, 128. https://doi.org/10.1021/acs.jpca.4c04928

1.2. Results of test calculations for ground- and excited-states of confined systems (M24).

Delivered – As scheduled, the work of the second sub-deliverable has been completed.

Scientific publications proving the achievement of the deliverable are:

1. Vindel-Zandbergen P.; Kędziera D., Żółtowski M.; Kłos J.; Żuchowski P., Felker P.; Lique F.; Balic Z. H2O–HCN complex: A new potential energy surface and intermolecular rovibrational states from rigorous quantum calculations. The Journal of Chemical Physics, 2023, 159. https://doi.org/10.1063/5.0173751

2. Krupka, K. M.; de Lara-Castells, M. P. Support Effects on Conical Intersections of Jahn-Teller Fluxional Metal Clusters on the Sub-Nanoscale. Physical Chemistry Chemical Physics, 2024. https://doi.org/10.1039/d4cp03271c.

3. Krupka, K. M.; Fernández, B; de Lara-Castells, M. P. Ab Initio Benchmarking on Unsupported and Coronene‐Supported Silver Atomic Clusters: Interplay Between Jahn–Teller Distortions and Fluxionality. Small Structures, 2026, 7. https://doi.org/10.1002/sstr.202500478. Cover Feature – https://doi.org/10.1002/sstr.70314

4. de Lara‐Castells, M. P. An Ab Initio Journey toward the Molecular‐Level Understanding and Predictability of Subnanometric Metal Clusters. Small Structures, 2024, 5. https://doi.org/10.1002/sstr.202400147. Cover feature – https://doi.org/10.1002/sstr.202470048.

1.3. Creation of diverse datasets (M36).

Delivered – The work on the third sub-deliverable has been also completed.

Scientific publications proving the achievement of the deliverable are:

1. Krupka, K. M; Mitrushchenkov, A.O., de Lara-Castells, M. P. Role of Anharmonicity and Bimetallic Intermixing in the IR and Raman Spectra of Cun and PdnCu6-n Clusters (n<7). Ab Initio Benchmarking of DFT. Small Structures, 2026, 7. https://doi.org/10.1002/sstr.70450. Cover Feature – https://doi.org/10.1002/sstr.70488

2. Podeszwa R.; Witek H. A.: Chou Ch.-P. ZZPolyCalc: An open-source code with fragment caching for determination of Zhang-Zhang polynomials of carbon nanostructures. Computer Physics Communications, 2024, 301. https://doi.org/10.1016/j.cpc.2024.109210

1.4. Assessment of methods against created datasets (M48).

Delivered – The work on the fourth sub-deliverable has been also completed.

Scientific publications proving the achievement of the deliverable are:

1. Krupka, K. M.; Krzemińska, A.; de Lara-Castells, M. P. A Practical Post-Hartree-Fock Approach Describing Open-Shell Metal Cluster-Support Interactions. Application to Cu3 Adsorption on Benzene/Coronene. RSC Advances, 2024, 14, 31348–31359. https://doi.org/10.1039/d4ra05401f.

2. Krupka, K. M; Mitrushchenkov, A.O., de Lara-Castells, M. P. Role of Anharmonicity and Bimetallic Intermixing in the IR and Raman Spectra of Cun and PdnCu6-n Clusters (n<7). Ab Initio Benchmarking of DFT. Small Structures, 2026, 7. https://doi.org/10.1002/sstr.70450. Cover Feature – https://doi.org/10.1002/sstr.70488.

3. Fernández,B. Handbook of Electronic Structure Theory: Methods and Applications., 2026, 381-394. DOI: https://doi.org/10.1016/B978-0-443-26596-9.00018-1

Deliverable 2. Descriptors of systems under confinement (M24); Development of Force-Fields using Machine-Learning (M48); Development of embedding potentials describing confining environments along with Working Group 3 (M36).

Ab initio interatomic potentials for copper subnanometric clusters interacting with polycyclic aromatic hydrocarbons (DOI: 10.1039/D4RA05401F) will be reparametrized using machine learning techniques. Machine learning training datasets of intermolecular interactions involving metals and metal oxide clusters can be derived from the COSY- INTER-NANO dataset (https://github.com/piotrzuchowski/COSY_Inter_Nano). Additionally, both ab initio and DFT-based ML models (DOI: 10.1021/acs.jctc.4c00643) were extended to confined systems with embedding potentials developed during the 3rd Grant Period.

2.1. Descriptors of systems under confinement (M24)

Delivered – The work on the first sub-deliverable has been completed.

Scientific publications proving the achievement of the deliverable are:

1. Vindel-Zandbergen P.; Kędziera D., Żółtowski M.; Kłos J.; Żuchowski P., Felker P.; Lique F.; Balic Z. H2O–HCN complex: A new potential energy surface and intermolecular rovibrational states from rigorous quantum calculations. The Journal of Chemical Physics, 2023, 159. https://doi.org/10.1063/5.0173751

2. Tyrcha B.; Gupta T; Patkowski K.; Żuchowski P.S. Analytical Derivatives of Symmetry-Adapted Perturbation Theory Corrections for Interaction-Induced Properties. Journal of Chemical Theory and Computation, 2025, 21. https://doi.org/10.1021/acs.jctc.5c00238

3. García-Alonso E.; Roongcharoen T; Zuchowski P.; Fortunelli A. In Search of Structure’ Links Across Length Scales: Crossover Among Structural Motifs, Energetics, and Magic Systems in Subnanometer Transition Metals Clusters. Small Structures, 2026, 7. https://doi.org/10.1002/sstr.202500345. Cover – https://doi.org/10.1002/sstr.70238

2.2. Development of Force-Fields using Machine-Learning (M48)

Delivered – The work on the second sub-deliverable has been complete.

Scientific publications proving the achievement of the deliverable are:

1. Derbali, E.; Ajili ,Y; Mehnen, B.; Żuchowski, P.; Kędziera, D.; Al-Mogren, M. M.; Jaidane N.-E.;Hochlaf, M. Towards the generation of potential energy surfaces of weakly bound medium sized molecular systems: The case of benzonitrile – He complex. Phys. Chem. Chem. Phys., 2023, 25. Font Cover: https://doi.org/10.1039/D3CP90226A

2. Rodríguez-López,O. Martínez-Núñez,E.; Vázquez,S.A.; Fernández,B. Efficient Machine Learning Barrier Height and Reaction Enthalpy Corrections for Low- and Midlevel Quantum Mechanical Calculations. Small Structures, 2026, 7. https://doi.org/10.1002/sstr.70504.

2.3. Development of embedding potentials describing confining environments along with Working Group 3 (M36).

Delivered – The work on the third sub-deliverable has been complete.

Scientific publications proving the achievement of the deliverable are: