Computational investigation of structure, dynamics and nucleation kinetics of a family of modified Stillinger-Weber model fluids in bulk and free-standing thin films

Abstract

In recent decades, computer simulations have found increasingly widespread use as powerful tools of studying phase transitions in wide variety of systems. In the particular and very important case of aqueous systems, the commonly used force-fields tend to offer quite different predictions with respect to a wide range of thermodynamic and kinetic properties, including the ease of ice nucleation, the propensity to freeze at a vapor-liquid interface, and the existence of a liquid-liquid phase transition. It is thus of fundamental and practical interest to understand how different features of a given water model affect its thermodynamic and kinetic properties. In this work, we use the forward-flux sampling technique to study the crystallization kinetics of a family of modified Stillinger-Weber (SW) potentials with energy ($\epsilon$) and length ($\sigma$) scales taken from the monoatomic water (mW) model, but with different tetrahedrality parameters ($\lambda$). By increasing $\lambda$ from 21 to 24, we observe the nucleation rate increases by 48 orders of magnitude at a supercooling of $\zeta =T/T_m=0.845$. Using classical nucleation theory, we are able to demonstrate that this change can largely be accounted for by the increase in $|\Delta \mu |$, the thermodynamic driving force. We also perform rate calculations in freestanding thin films of the supercooled liquid, and observe a crossover from a surface-enhanced crystallization at $\lambda =21$ to a bulk-dominated crystallization for $\lambda \ge 22$.

10 pages, 9 figures, five tables

References in corpus (7)

• Direct Calculation of Ice Homogeneous Nucleation Rate for a Molecular Model of Water
• Forward Flux Sampling-type schemes for simulating rare events: Efficiency analysis
• Homogeneous ice nucleation evaluated for several water models
• Local order parameters for use in driving homogeneous ice nucleation with all-atom models of water
• Tuning the liquid-liquid transition by modulating the hydrogen bond angular flexibility in a model for water
• Suppression of Sub-surface Freezing in Free-Standing Thin Films of a Coarse-grained Model of Water
• The Effect of Substrate on Thermodynamic and Kinetic Anisotropies in Atomic Thin Films

Cited by in corpus (14)

• Crystal Nucleation in Liquids: Open Questions and Future Challenges in Molecular Dynamics Simulations
• Thermodynamically Driven Assemblies and Liquid-liquid Phase Separations in Biology
• Microscopic Mechanism and Kinetics of Ice Formation at Complex Interfaces: Zooming in on Kaolinite
• Ice Formation on Kaolinite: Insights from Molecular Dynamics Simulations
• Studying Rare Events using Forward-Flux Sampling: Recent Breakthroughs and Future Outlook
• Unravelling the Origins of Ice Nucleation on Organic Crystals
• Forward Flux Sampling Calculation of Homogeneous Nucleation Rates from Aqueous NaCl Solutions
• Forward-Flux Sampling with Jumpy Order Parameters
• Induced Charge Anisotropy: a Hidden Variable Affecting Ion Transport through Membranes
• How to Quantify and Avoid Finite Size Effects in Computational Studies of Crystal Nucleation: The Case of Heterogeneous Ice Nucleation
• Role of Nanoscale Interfacial Proximity in Contact Freezing in Water
• The barrier to ice nucleation in monatomic water
• Perspective: Surface Freezing in Water: A Nexus of Experiments and Simulations
• How to quantify and avoid finite size effects in computational studies of crystal nucleation: The case of homogeneous crystal nucleation