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Proton-driven many-body interactions and structural organization in He n H+ clusters
María Judit Montes de Oca-Estévez1, Javier Hernández-Rojas2, Rita Prosmiti1
1Institute of Fundamental Physics, CSIC (IFF-CSIC) Serrano 123 28006 Madrid Spain rita@iff.csic.es.
RSC Advances
|March 2, 2026
Summary
We describe interactions in helium-n-hydronium (HenH+) clusters using advanced computational methods. Larger clusters require higher-order terms for accurate modeling, revealing structural organization and quantum effects influencing stability.
Area of Science:
- Chemical Physics
- Computational Chemistry
- Quantum Mechanics
Background:
- Proton solvation in helium clusters (HenH+) is crucial for understanding microsolvation.
- Experimental studies show varying stability patterns for these clusters.
- Accurate theoretical descriptions require sophisticated computational approaches.
Purpose of the Study:
- To systematically describe the interactions governing HenH+ clusters.
- To develop a reliable computational framework for predicting cluster stability.
- To interpret experimental observations of cluster stability trends.
Main Methods:
- Utilizing gold-standard *ab initio* data.
- Employing a many-body expansion formalism with two-, three-, and four-body potentials.
- Generating potentials via CCSD(T)/CBS calculations and machine learning.
- Performing global minimum searches to determine structural organization.
Main Results:
- Accurate modeling of larger clusters necessitates up to four-body interaction terms.
- Structural organization involves sequential He atom binding to a HeH+He core.
- Increasing delocalization of weakly bound He atoms suggests superfluid-like behavior.
- Energetics reproduce experimental stability for n ≤ 13, with quantum effects impacting larger clusters.
Conclusions:
- Higher-order many-body effects and quantum contributions are essential for accurate proton microsolvation in He.
- The developed framework reliably interprets experimental stability trends in proton-bound noble-gas clusters.
- This work provides insights into the interplay of structure, quantum effects, and stability in atomic clusters.
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