Department of Physics, University of Massachusetts, Amherst, Massachusetts 01003, USA.
Santa Fe Institute, 1399 Hyde Park Road, Santa Fe, New Mexico 87501, USA.
Phys Rev E. 2017 Jun;95(6-1):063315. doi: 10.1103/PhysRevE.95.063315. Epub 2017 Jun 27.
Population annealing is a sequential Monte Carlo scheme well suited to simulating equilibrium states of systems with rough free energy landscapes. Here we use population annealing to study a binary mixture of hard spheres. Population annealing is a parallel version of simulated annealing with an extra resampling step that ensures that a population of replicas of the system represents the equilibrium ensemble at every packing fraction in an annealing schedule. The algorithm and its equilibration properties are described, and results are presented for a glass-forming fluid composed of a 50/50 mixture of hard spheres with diameter ratio of 1.4:1. For this system, we obtain precise results for the equation of state in the glassy regime up to packing fractions φ≈0.60 and study deviations from the Boublik-Mansoori-Carnahan-Starling-Leland equation of state. For higher packing fractions, the algorithm falls out of equilibrium and a free volume fit predicts jamming at packing fraction φ≈0.667. We conclude that population annealing is an effective tool for studying equilibrium glassy fluids and the jamming transition.
群体退火是一种适合模拟具有粗糙自由能景观的系统平衡状态的序贯蒙特卡罗方案。在这里，我们使用群体退火来研究硬球的二元混合物。群体退火是模拟退火的并行版本，它增加了一个重采样步骤，以确保系统的副本群体在退火方案的每个堆积分数处代表平衡集合。描述了算法及其平衡性质，并为直径比为 1.4:1 的硬球 50/50 混合物组成的玻璃形成流体呈现了结果。对于这个系统，我们在玻璃态范围内获得了精确的状态方程结果，直到堆积分数φ≈0.60，并研究了偏离 Boublik-Mansoori-Carnahan-Starling-Leland 状态方程的情况。对于更高的堆积分数，算法会失去平衡，自由体积拟合预测在堆积分数φ≈0.667 处会发生堵塞。我们得出结论，群体退火是研究平衡玻璃态流体和堵塞转变的有效工具。
