arXiv subjects

Chaohong Wang

Publications and source records attributed to Chaohong Wang.

3 recordsLinked to original sources

arXiv2024

Inverse Design Method with Enhanced Sampling for Complex Open Crystals: Application to Novel Zeolite Self-Assembly in a Coarse-Grained Model

Optimizing the synthesis of zeolites and exploring novel frameworks offer pivotal opportunities and challenges in materials design. While inverse design proves highly effective for simpler crystals, its application to intricate structures like zeolites poses severe challenges. Here, we introduce an innovative inverse design workflow tailored to efficiently reproduce target zeolite frameworks in a binary coarse-grained model using enhanced sampling molecular dynamics simulations. This workflow integrates an evolutionary parameter optimization strategy with a variant of the seeding approach. Using this method, we successfully reproduce Z1 and SGT zeolites, and Type-I clathrates, find new optimal parameters for known phases, such as the SOD and CFI, and even discover novel frameworks, such as Z5. This is done within a simple coarse-grained model for a tetrahedra-forming component and a structure-directing agent. Our methodology not only enables the screening of synthesis protocols but also facilitates the discovery of hypothetical zeolites.

cond-mat.mtrl-sci↗

arXiv2020

Classical nucleation theory of ice nucleation: second-order correction of thermodynamic parameters

Accurate estimate of nucleation rate is crucial for the study of ice nucleation and ice-promoting/anti-freeze strategies. Within the framework of Classical Nucleation Theory (CNT), the estimate of ice nucleation rate is very sensitive to thermodynamic parameters, such as chemical potential difference between water and ice $Δμ$ and ice-water interfacial free energy $γ$. However, even today, there are still many contradictions and approximations in the estimating of these thermodynamic parameters, introducing large uncertainty to the estimate of the ice nucleation rate. Herein, starting from the basic concepts, for a general solid-liquid crystallization system, we expand the Gibbs-Thomson (GT) equation to second order, and derive the second-order analytical formulas of $Δμ$, $γ$ and nucleation barrier $ΔG$ with combining molecular dynamics (MD) simulations. These formulas describe well the temperature dependence of these thermodynamic parameters. Our results can provide a method of estimating $Δμ$, $γ$ and $ΔG$.

cond-mat.soft↗

arXiv2020

The Effect of Dipole from $γ$-AgI Substrates on Heterogeneous Ice Nucleation

Heterogeneous ice nucleation is one of the most common and important process in the physical environment. AgI has been proved to be an effective ice nucleating agent in the process of ice nucleation. However, the microscopic mechanism of AgI in heterogeneous ice nucleation has not been fully understood. Molecular dynamics simulations are applied to investigate the ability of which kinds of $γ$-AgI substrate can promote ice nucleation by changing the dipole of $γ$-AgI on the substrate, we conclude that the dipole of $γ$-AgI on the substrate can affect the conformation of ice nucleation. The surface ions with positive charge on the substrate may promote ice nucleation, while there is no ice nucleation founded on the surface ions with negative charge. $γ$-AgI substrates affect ice nucleation through adjust the orientations of water molecules near the surfaces.

cond-mat.mtrl-sci↗