Structural and dynamical anomalies of a Gaussian core fluid: A mode-coupling theory study

Shall, Lindsey Ann; Егоров, С. А.

doi:10.1063/1.3429354

Cited by 15 publications

(21 citation statements)

References 51 publications

(170 reference statements)

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“…At T = T th , however, RPA works poorly around r = 0, as expected from Eq. (15). On the other hand, RPA's results perfectly match with the simulation results at larger r 's including the first shell peaks.…”

Section: B High Temperature Regimesupporting

confidence: 77%

“…Recently, thermodynamic and transport anomalies of the fluid phase in the vicinity of the reentrant peaks are investigated. 10,[12][13][14][15][16] Microscopic and structural properties such as the static structure factor in the fluid phase are also reported and documented. 6,7,9,11 These studies revealed that, as the density increases beyond the reentrant peak but at a fixed temperature, thermodynamic and structural properties of GCM becomes more ideal-gas-like, signaled by the lowering of the peak of the structure factors and the better agreement with simple approximations such as the random phase approximation (RPA).…”

Section: Introductionmentioning

confidence: 99%

“…GCM was first introduced by Stillinger 4 and has been studied by many groups. [5][6][7][8][9][10][11][12][13][14][15][16] Despite of its simple form of the pair potential, GCM exhibits many typical thermodynamic behaviors of the ultra-soft particles. According to thermodynamic phase diagram obtained by numerical simulations, 4,8 GCM basically behaves such as hard spheres at very low densities and temperatures; the crystalline structure in the solid phase is fcc and the freezing/melting temperatures sharply increase with density.…”

Section: Introductionmentioning

confidence: 99%

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Thermodynamic and structural properties of the high density Gaussian core model

Ikeda

Miyazaki

2011

The Journal of Chemical Physics

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We numerically study thermodynamic and structural properties of the one-component Gaussian core model at very high densities. The solid-fluid phase boundary is carefully determined. We find that the density dependence of both the freezing and melting temperatures obey the asymptotic relation, log T f , log T m ∝ −ρ 2/3 , where ρ is the number density, which is consistent with Stillinger's conjecture. Thermodynamic quantities such as the energy and pressure and the structural functions such as the static structure factor are also investigated in the fluid phase for a wide range of temperature above the phase boundary. We compare the numerical results with the prediction of the liquid theory with the random phase approximation (RPA). At high temperatures, the results are in almost perfect agreement with RPA for a wide range of density, as it has already been shown in the previous studies. In the low temperature regime close to the phase boundary line, although RPA fails to describe the structure factors and the radial distribution functions at the length scales of the interparticle distance, it successfully predicts their behaviors at longer length scales. RPA also predicts thermodynamic quantities such as the energy, pressure, and the temperature at which the thermal expansion coefficient becomes negative, almost perfectly. Striking ability of RPA to predict thermodynamic quantities even at high densities and low temperatures is understood in terms of the decoupling of the length scales which dictate thermodynamic quantities from the interparticle distance which dominates the peak structures of the static structure factor due to the softness of the Gaussian core potential.

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Section: B High Temperature Regimesupporting

confidence: 77%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Thermodynamic and structural properties of the high density Gaussian core model

Ikeda

Miyazaki

2011

The Journal of Chemical Physics

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“…We numerically study the monodisperse GCM in three dimension and show that nucleation is suppressed at very high densities and that the system exhibits canonical glassy behavior in the supercooled state. The quantitative agreement of the dynamical properties with the theoretical predictions is better than that of all previously investigated model glass formers.The thermodynamic and dynamic properties of the GCM have recently been vigorously investigated [5,9,[12][13][14]. Most previous studies, however, focused on the density regime ρσ 3 1, where the phase diagram exhibits reentrant melting.…”

mentioning

confidence: 99%

“…The thermodynamic and dynamic properties of the GCM have recently been vigorously investigated [5,9,[12][13][14]. Most previous studies, however, focused on the density regime ρσ 3 1, where the phase diagram exhibits reentrant melting.…”

mentioning

confidence: 99%

Glass Transition of the Monodisperse Gaussian Core Model

Ikeda

Miyazaki

2011

Phys. Rev. Lett.

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We numerically investigate the dynamical properties of the one-component Gaussian core model in supercooled states. We find that nucleation is increasingly suppressed with increasing density. The system concomitantly exhibits glassy, slow dynamics characterized by the two-step stretched exponential relaxation of the density correlation and a drastic increase of the relaxation time. We also find a weaker violation of the Stokes-Einstein relation and a smaller non-Gaussian parameter than in typical model glass formers, implying weaker dynamic heterogeneities. Additionally, the agreement of the simulation data with the prediction of mode-coupling theory is exceptionally good, indicating that the nature of the slow dynamics of this ultra-soft particle fluid is mean-field-like. This fact may be understood as a consequence of the long-range nature of the interaction. The nature of the glass transition is surrounded by controversy. Several scenarios have been proposed to explain the drastic slowing down of dynamics of supercooled fluids near the glass transition point [1][2][3]. Numerical simulation of simple model fluids is an ideal tool to test these competing scenarios. However, the typical model fluids studied so far, such as Lennard-Jones, soft-core, and hard-sphere mixtures, have short-ranged, strong repulsive interactions in common, which dictate their thermodynamic, structural, and dynamical properties and render the results of these models qualitatively similar [4]. A new class of model glass formers is desirable to diversify our pictures and perspectives on the glass transition within the limited accessible time windows of the simulations. Recently, ultra-soft particle fluids have attracted particular attention in soft-materials science [5]. They are systems composed of spherical particles interacting with bounded and weak repulsions and are a good model for various soft materials, such as star-polymers and dendrimers. The absence of the hard-core-like repulsion makes the thermodynamic and dynamic behaviors of this class of systems extremely rich compared with standard molecular systems. Their phase diagrams exhibit exotic and counterintuitive properties, including a stable fluid phase at high temperatures for arbitrary densities, re-melting of solids at higher densities, and complex crystalline phases at low temperatures [5]. The dynamics of the ultra-soft particles fluids also exhibits rich and nontrivial behaviors [6][7][8][9].In this Letter, we consider the simplest version of ultrasoft particles, i.e., the Gaussian core model (GCM) fluid originally introduced by Stillinger [10]. The GCM interaction is given bywhere ǫ and σ characterize the energy and length scales, respectively. The GCM is an ideal model to study glassy dynamics because its thermodynamic phase diagram is relatively simple. Other ultra-soft particles, such as Hertzian spheres and star-polymers, exhibit complex crystalline phases, which may affect the dynamics in the supercooled state [6,11]. We numerically study the monodisperse GCM in th...

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Self-diffusion of nanoscale particles with hard and soft sphere models

Sun

Wang

2020

Colloid Polym Sci

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Structural and dynamical anomalies of a Gaussian core fluid: A mode-coupling theory study

Cited by 15 publications

References 51 publications

Thermodynamic and structural properties of the high density Gaussian core model

Thermodynamic and structural properties of the high density Gaussian core model

Glass Transition of the Monodisperse Gaussian Core Model

Self-diffusion of nanoscale particles with hard and soft sphere models

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