Microscopic structure and thermodynamics of a core-softened model fluid: insights from grand canonical Monte Carlo simulations and integral equations theory.
Microscopic structure and thermodynamics of a core-softened model fluid: insights from grand canonical Monte Carlo simulations and integral equations theory.
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DOI：
10.1063/1.3125930
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发表时间：
2009-05
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影响因子：
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通讯作者：
O. Pizio;H. Domínguez;Yurko Duda;S. Sokołowski
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文献类型：
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作者：
O. Pizio;H. Domínguez;Yurko Duda;S. Sokołowski
利用巨正则MonteCarlo方法，结合超网链和Rogers-Young封闭的Ornstein-Zernike积分方程，研究了三维各向同性核软化模型流体的微观结构和热力学性质.应用模拟工具允许获得洞察力的模型的属性，除了可用的分子动力学数据的其他作者。讨论了密度-化学势投影中的物态方程，并探讨了化学势沿着不同等容线的温度依赖性。的结构和热力学性质的异常行为的区域的限制建立通过调查导致的状态方程，对过剩熵的贡献，和平移序参数的衍生物。此外，我们评估的热容的温度和密度的依赖性。微观结构的对分布函数和相应的结构因子进行了讨论。我们已经建立了超网链近似是不成功的捕获区域的异常相比，Rogers-Young近似，但对于高流体密度是非常准确的。因此，我们已经研究了在这个理论框架内的结晶转变的开始。此外，使用复制的Ornstein-Zernike积分方程与超网链封闭，我们探讨了玻璃化转变的可能性，并描述了它的过渡密度和化学势。
We have studied the microscopic structure and thermodynamic properties of isotropic three-dimensional core-softened model fluid by using extensive grand canonical Monte Carlo computer simulations and Ornstein-Zernike integral equations with hypernetted chain and Rogers-Young closures. Applied simulation tools permit to obtain insights into the properties of the model in addition to available molecular dynamics data of other authors. We discuss equation of state in the density-chemical potential projection and explore the temperature dependence of the chemical potential along different isochores. The limits of the region of anomalous behavior of the structural and thermodynamic properties are established by investigating derivatives resulting from the equation of state, pair contribution to excess entropy, and translational order parameter. Besides, we evaluate the dependence of the heat capacity on temperature and density. The microscopic structure is discussed in terms of the pair distribution functions and corresponding structure factors. We have established that the hypernetted chain approximation is not successful to capture the region of anomalies in contrast to Rogers-Young approximation, but is very accurate for high fluid densities. Thus we have studied the onset for crystallization transition within this theoretical framework. Moreover, using the replicated Ornstein-Zernike integral equations with hypernetted chain closure, we explore the possibility of glass transition and described it in terms of transition density and chemical potential.