anthonca

• Camposano, Anthony Val Canillas; Hafreager, Anders; Malthe-Sørenssen, Anders & Sveinsson, Henrik Andersen (2026). Silica-water model using the Vashishta force field. Journal of Chemical Physics. ISSN 0021-9606. 165(10). doi: 10.1063/5.0343021. Fulltekst i vitenarkiv
• Camposano, Anthony Val Canillas; Nordhagen, Even Marius; Sveinsson, Henrik Andersen & Malthe-Sørenssen, Anders (2025). Genetic Algorithm Workflow for Parameterization of a Water Model Using the Vashishta Force Field. Journal of Physical Chemistry B. ISSN 1520-6106. 129(4), s. 1331–1342. doi: 10.1021/acs.jpcb.4c06389. Fulltekst i vitenarkiv Vis sammendrag

  Water participates in countless processes on Earth, and the properties of mineral surfaces can be drastically changed in the presence of water. For example, the fracture toughness of silica glass is reduced by 25% for water-filled cracks than for dry cracks [Geophys. Res.: Solid Earth 2018, 123, 9341–9354]. An accurate description of water is therefore essential for modeling the behavior of minerals in aqueous environments and, in particular, for modeling dynamic processes such as fracture, where the mechanical response of water may play an important role. On the molecular scale, molecular dynamics simulations with empirical force field methods provide a way to study large molecular systems at a relatively low computational cost. Many water models have been developed previously; however, a computationally cheap water model capable of describing reactions with minerals is lacking. Here, we present a parametrization of the water potential using the Vashishta potential form [Phys. Rev. B 1990, 41, 12197–12209]. For this 3-point water model, we obtain good agreement with experimental transport and liquid–vapor properties. Importantly, the Vashishta form opens up compatibility with existing silica glass models, thus enabling the simulation of mineral–water interactions.

• Camposano, Anthony Val Canillas; Nordhagen, Even Marius; Malthe-Sørenssen, Anders & Sveinsson, Henrik Andersen (2025). An Extended Energy-Biased Aggregation-Volume-Bias Monte Carlo (EB-AVBMC) Method for Nucleation Simulation of a Reactive Water Potential. Journal of Chemical Theory and Computation. ISSN 1549-9618. 21(14), s. 6769–6776. doi: 10.1021/acs.jctc.5c00722. Fulltekst i vitenarkiv

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• Camposano, Anthony Val Canillas; Sveinsson, Henrik Andersen & Malthe-Sørenssen, Anders (2024). Machine Learning an All-Atom Empirical Force Field for a Water-Silica System. Fulltekst i vitenarkiv Vis sammendrag

  Molecular modeling of the interaction between silica and water provides a better understanding of how water affects rocks and glasses at the nanoscale. Here, we parametrize a new classical dissociative force field for the water–silica system. We create a classical force field capable of reactive interactions between all chemical species in the water–silica system, using the same functional form by Vashishta et al. to describe bulk water, silica, and silica–water interactions. Using a hierarchical genetic algorithm as a global optimizer and the Nelder-Mead simplex algorithm as a local optimizer, we parameterized the Vashishta force field to reproduce the density, transport properties, and vapor-liquid properties of water. We then used the same method to obtain water–silica interaction parameters to reproduce gas phase orthosilicic geometry and silica surface properties such as silanol concentration, heat of immersion, and the wettability angle of water on a silica surface. For oxygen–silicon interactions in silica, we reuse an existing Vashishta potential parameter set that has been parameterized to reproduce bulk mechanical behavior, surface properties, and fracture properties. Our developed force field can be used to study processes such as dissolution, friction, and stress corrosion fracture in the presence of water over a wide range of thermodynamic conditions for larger-scale and longer-scale simulations.

• Camposano, Anthony Val Canillas; Sveinsson, Henrik Andersen & Malthe-Sørenssen, Anders (2023). Tuning Vashishta Potential for Water. Fulltekst i vitenarkiv
• Camposano, Anthony Val Canillas (2025). Parameterization of a Reactive Silica-Water Model using the Vashishta Functional Form. Universitetet i Oslo. Fulltekst i vitenarkiv Vis sammendrag

  Water is known to weaken materials like rock and glass, a critical process in everything from earthquake dynamics to the durability of ceramics. Computer simulations can help us understand this weakening at the atomic level, showing how water molecules interact with a material as it breaks. However, existing simulation methods have faced a trade-off: they are often too slow to model the millions of atoms needed to see a crack propagate realistically, or they are not accurate enough to capture the chemical reactions happening at the crack's tip. This thesis presents a new, computationally efficient model that tackles this dilemma. We have developed a tool that is both fast and allows for chemical reactions by using a specific framework, the Vashishta potential, to model atomic interactions. We optimized the model to successfully simulate water's behavior over a wide range of conditions and its reaction with a silica surface. These capabilities enable larger and longer simulations, providing a powerful new resource for understanding material failure in aqueous environments in geology, materials science, and engineering.

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