Bryk Taras, Ruocco Giancarlo, Seitsonen Ari Paavo
Institute for Condensed Matter Physics of National Academy of Sciences of Ukraine, Lviv, 79011, Ukraine.
Institute of Applied Mathematics and Fundamental Sciences, Lviv National Polytechnic University, Lviv, 79013, Ukraine.
Sci Rep. 2023 Oct 23;13(1):18042. doi: 10.1038/s41598-023-45338-2.
One of the fundamental quantities in dynamics of the liquid state, the adiabatic speed of sound [Formula: see text], is extremely difficult to predict from computer simulations, especially in ab initio simulations. Here we derive an expression for the instantaneous correlator of fluctuations of longitudinal component of stress tensor, which contains [Formula: see text] along with others quantities easy accessible via classical and ab initio computer simulations. We show that the proposed methodology works well in the case of Lennard-Jones and soft-sphere simple fluids, Kr-Ar liquid mixture in connection with simulations with effective pair interactions as well as for liquid Sb, fluid Hg and molten NaCl from ab initio simulations.
液态动力学中的一个基本量，即绝热声速[公式：见正文]，极难通过计算机模拟来预测，尤其是在从头算模拟中。在此，我们推导了一个关于应力张量纵向分量涨落的瞬时关联函数的表达式，该表达式除了其他量外还包含[公式：见正文]，这些量可通过经典和从头算计算机模拟轻松获得。我们表明，所提出的方法在 Lennard-Jones 和软球简单流体、具有有效对相互作用模拟的 Kr-Ar 液体混合物以及从头算模拟的液态 Sb、流体 Hg 和熔融 NaCl 的情况下都能很好地发挥作用。
