The search for local structures within a disordered medium has led to proposals of several methods for probing transient short-range symmetry in a homogeneous mono-atomic liquid. We offer a comparison of different characterizations of such local structure in an in-homogeneous liquid. We simulate the interfaces between a Lennard-Jones liquid and (i) a flat Lennard-Jones wall, (ii) a wall of face-centered cubic-packed Lennard-Jones particles, and (iii) a Lennard-Jones vapor. The interface density distributions in cases (i) and (ii) have oscillations extending several particle diameters into the bulk liquid, while that in case (iii) the interface density distribution monotonically decays from the bulk liquid to the vapor. We search for transient ordered fluctuations, which we identify with local ordered structures, using the Aperture Cross Correlation Function of the system. We find that only particles in the FCC-liquid interface that are in the two layers closest to the FCC surface exhibit preferred four-fold symmetry. Furthermore, the absence of three- or five-fold symmetry peaks in the Aperture Cross Correlation Function of the liquid-vapor interface yields a different picture of that interface than derived from the high density of bi-pyramidal clusters found in the Topological Cluster Classification study (Molecular Physics, 109 (7-10), 1393-1402 (2011)). While the Aperture Cross Correlation Function results need not be viewed as contradictory with the Topological Cluster Classification results, we argue the advantages of using the former to characterize transient ordered fluctuations as being both experimentally accessible in favorable cases and not reliant on a list of structures.
Comment on: "Static correlations functions and domain walls in glass-forming liquids: The case of a sandwich geometry" [J. Chem. Phys. 138, 12A509 (2013)]
Density Functional Theory of Inhomogeneous Liquids IV. Squared-gradient approximation and Classical Nucleation Theory
发展了修正核Van der Waals密度泛函理论模型的平方梯度近似。一个简单的，明确的SGA系数的表达式只涉及体状态方程和相互作用势。该模型解决了平面界面和球形集群，并被证明是定量准确的计算机模拟比较。介绍了一种基于分段线性密度分布求解SGA的近似技术，并给出了合理的零阶近似模型的数值解。球形团簇的分段线性模型被证明是经典成核理论的自然延伸，并用于澄清以前在液-汽成核中观察到的一些非经典效应。成核途径进行了研究，使用约束能量最小化和最速下降技术。
Response to "Comment on Static correlations functions and domain walls in glass-forming liquids: The case of a sandwich geometry" [J. Chem. Phys. 144, 227101 (2016)]
Building on the recently derived inhomogeneous mode-coupling theory, we extend the generalised mode-coupling theory of supercooled liquids to inhomogeneous environments. This provides a first-principles-based, systematic and rigorous way of deriving high-point dynamical susceptibilities from variations of the many-body dynamic structure factors with respect to their conjugate field. This new framework allows for a novel and fully microscopic possibility to probe for collective relaxation mechanisms in supercooled liquids near the mode-coupling glass transition.
The Barker-Henderson perturbation theory is a bedrock of liquid-state physics, providing quantitative predictions for the bulk thermodynamic properties of realistic model systems. However, this successful method has not been exploited for the study of inhomogeneous systems. We develop and implement a first-principles 'Barker-Henderson density functional', thus providing a robust and quantitatively accurate theory for classical fluids in external fields. Numerical results are presented for the hard-core Yukawa model in three dimensions. Our predictions for the density around a fixed test partic…
Comment on Geometrical Control of Active Turbulence in Curved Topographies
在最近的信皮尔斯等。等，Phys. Rev. Lett. 122，168002（2019）作者研究了二维有源液晶的湍流动力学，该液晶被约束到环面的表面。底层模型结合了不可压缩表面纳维-斯托克斯方程与摩擦和主动强迫的表面Landau-de Gennes模型的液晶。为了数值求解表面纳维-斯托克斯方程，考虑了涡量流函数方法。这种方法是不适当的表面上，不是简单连接-如所考虑的环面-由于非平凡的谐波向量场。我们将解释基本情况，并提供细节和例子来反驳皮尔斯等人的论点。等，Phys. Rev. Lett. 122，168002（2019）。
