论文标题
计算眼镜的自由能的数值方法
Numerical method for computing the free energy of glasses
论文作者
论文摘要
我们提出了一种数值技术，以计算无法可逆地制备的玻璃的平衡自由能。对于此类系统，无法使用用于通过外推估计自由能的标准技术。取而代之的是，我们使用一个程序，该过程将系统吸引的盆地的平衡分区函数（局部势能最小值）的吸引力。如果所有相关的固有结构都可以在（超冷）液相中进行充分采样，那么我们的方法将是严格的。在任何有限的模拟中，我们都会错过在极低温度下占主导地位的较低能源固有结构。我们发现，即使在温度下降到玻璃过渡温度的三分之一时，我们对Kob-Andersen玻璃的自由能估计值也低于非常缓慢的冷却。当前的方法可以用于计算超稳定玻璃材料的化学潜力，并应估算其溶解度。
We propose a numerical technique to compute the equilibrium free energy of glasses that cannot be prepared quasi-reversibly. For such systems, standard techniques for estimating the free energy by extrapolation, cannot be used. Instead, we use a procedure that samples the equilibrium partition function of the basins of attraction of the different inherent structures (local potential energy minima) of the system. If all relevant inherent structures could be adequately sampled in the (supercooled) liquid phase, our approach would be rigorous. In any finite simulation, we will miss the lower-energy inherent structures that become dominant at very low temperatures. We find that our free energy estimates for a Kob-Andersen glass are lower than those obtained by very slow cooling, even at temperatures down to one third of the glass transition temperature. The current approach could be applied to compute the chemical potential of ultra-stable glassy materials, and should enable the estimation of their solubility.
