样品制备对低密度向高密度无定形冰转变的影响：基于势能景观的解释。

Influence of sample preparation on the transformation of low-density to high-density amorphous ice: An explanation based on the potential energy landscape.

机构信息

Department of Physics, Brooklyn College of the City University of New York, Brooklyn, New York 11210, USA and Ph.D. Programs in Chemistry and Physics, The Graduate Center of the City University of New York, New York, New York 10016, USA.

Department of Physics, Wesleyan University, Middletown, Connecticut 06459, USA.

出版信息

J Chem Phys. 2017 Jul 28;147(4):044501. doi: 10.1063/1.4993567.

DOI:10.1063/1.4993567

PMID:28764372

Abstract

Experiments and computer simulations of the transformations of amorphous ices display different behaviors depending on sample preparation methods and on the rates of change of temperature and pressure to which samples are subjected. In addition to these factors, simulation results also depend strongly on the chosen water model. Using computer simulations of the ST2 water model, we study how the sharpness of the compression-induced transition from low-density amorphous ice (LDA) to high-density amorphous ice (HDA) is influenced by the preparation of LDA. By studying LDA samples prepared using widely different procedures, we find that the sharpness of the LDA-to-HDA transformation is correlated with the depth of the initial LDA sample in the potential energy landscape (PEL), as characterized by the inherent structure energy. Our results show that the complex phenomenology of the amorphous ices reported in experiments and computer simulations can be understood and predicted in a unified way from knowledge of the PEL of the system.

摘要

实验和计算机模拟表明，非晶冰的转变行为取决于样品制备方法以及温度和压力的变化率。除了这些因素外，模拟结果还强烈依赖于所选择的水模型。我们使用 ST2 水模型的计算机模拟研究了低密度非晶冰（LDA）到高密度非晶冰（HDA）的压缩诱导转变的尖锐程度如何受到 LDA 制备的影响。通过研究使用广泛不同程序制备的 LDA 样品，我们发现 LDA 到 HDA 转变的尖锐程度与初始 LDA 样品在势能景观（PEL）中的深度相关，这由固有结构能量来表征。我们的结果表明，实验和计算机模拟中报道的非晶冰的复杂现象可以通过系统 PEL 的知识以统一的方式来理解和预测。