Instituto de Ciencia de Materiales de Madrid, Consejo Superior de Investigaciones Científicas, Campus de Cantoblanco, 28049 Madrid, Spain.
J Chem Phys. 2012 Sep 14;137(10):104505. doi: 10.1063/1.4750027.
Structural and thermodynamic properties of high-density amorphous (HDA) ice have been studied by path-integral molecular dynamics simulations in the isothermal-isobaric ensemble. Interatomic interactions were modeled by using the effective q-TIP4P/F potential for flexible water. Quantum nuclear motion is found to affect several observable properties of the amorphous solid. At low temperature (T = 50 K) the molar volume of HDA ice is found to increase by 6%, and the intramolecular O-H distance rises by 1.4% due to quantum motion. Peaks in the radial distribution function of HDA ice are broadened with respect to their classical expectancy. The bulk modulus, B, is found to rise linearly with the pressure, with a slope ∂B/∂P = 7.1. Our results are compared with those derived earlier from classical and path-integral simulations of HDA ice. We discuss similarities and discrepancies with those earlier simulations.
采用等压等温热力学系综的路径积分分子动力学模拟研究了高密度非晶冰（HDA）的结构和热力学性质。通过使用灵活水的有效 q-TIP4P/F 势能对原子间相互作用进行建模。量子核运动被发现会影响非晶固体的几个可观测性质。在低温（T=50 K）下，由于量子运动，HDA 冰的摩尔体积增加了 6%，分子内 O-H 距离增加了 1.4%。与经典期望相比，HDA 冰的径向分布函数的峰值变宽。体弹性模量 B 被发现随压力呈线性增加，斜率 ∂B/∂P = 7.1。我们的结果与先前从 HDA 冰的经典和路径积分模拟中得出的结果进行了比较。我们讨论了与这些早期模拟的相似性和差异。
