Munaó Gianmarco, Saija Franz
Dipartimento di Scienza Matematiche e Informatiche, Scienze Fisiche e Scienze della Terra, Universitá degli Studi di Messina, Viale F. Stagno d'Alcontres 31, 98158 Messina, Italy.
Phys Chem Chem Phys. 2016 Apr 14;18(14):9484-9. doi: 10.1039/c6cp00191b. Epub 2016 Mar 16.
We report Monte Carlo results for the fluid structure of a system of dimeric particles interacting via a core-softened potential. More specifically, dimers interact through a repulsive pair potential of an inverse-power form, modified in such a way that the repulsion strength is softened for a given range of distances. The aim of such a study is to investigate how both the elongation of the dimers and the softness of the potential affect some features of the model. Our results show that the dimeric fluid exhibits both density and structural anomalies, even if the interaction is not characterized by two length scales. Upon increasing the aspect ratio of the dimers, such anomalies are progressively hindered, with the structural anomaly surviving even after the disappearance of the density anomaly. These results shed light on the peculiar behaviour of molecular systems of non-spherical shape, showing how geometrical and interaction parameters play a fundamental role in determining the presence of anomalies.
我们报告了通过核软化势相互作用的二聚体粒子系统的流体结构的蒙特卡罗结果。更具体地说，二聚体通过反幂形式的排斥对势相互作用，其修改方式是在给定距离范围内排斥强度被软化。这样一项研究的目的是研究二聚体的伸长和势的柔软度如何影响模型的某些特征。我们的结果表明，即使相互作用不以两个长度尺度为特征，二聚体流体也表现出密度和结构异常。随着二聚体纵横比的增加，这些异常逐渐受到阻碍，即使密度异常消失后结构异常仍然存在。这些结果揭示了非球形分子系统的特殊行为，展示了几何和相互作用参数在确定异常存在方面如何发挥基本作用。
