Wouterse A, Philipse A P
Van't Hoff Laboratory for Physical and Colloid Chemistry, Debye Institute, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands.
J Chem Phys. 2006 Nov 21;125(19):194709. doi: 10.1063/1.2390700.
We introduce a geometric analysis of random sphere packings based on the ensemble averaging of hard-sphere clusters generated via local rules including a nonoverlap constraint for hard spheres. Our cluster ensemble analysis matches well with computer simulations and experimental data on random hard-sphere packing with respect to volume fractions and radial distribution functions. To model loose as well as dense sphere packings various ensemble averages are investigated, obtained by varying the generation rules for clusters. Essential findings are a lower bound on volume fraction for random loose packing that is surprisingly close to the freezing volume fraction for hard spheres and, for random close packing, the observation of an unexpected split peak in the distribution of volume fractions for the local configurations. Our ensemble analysis highlights the importance of collective and global effects in random sphere packings by comparing clusters generated via local rules to random sphere packings and clusters that include collective effects.
我们基于通过局部规则生成的硬球团簇的系综平均，引入了一种对随机球体堆积的几何分析方法，这些局部规则包括硬球的非重叠约束。我们的团簇系综分析在体积分数和径向分布函数方面与随机硬球堆积的计算机模拟和实验数据匹配良好。为了对松散和致密的球体堆积进行建模，研究了通过改变团簇生成规则获得的各种系综平均。重要发现包括随机松散堆积的体积分数下限，该下限惊人地接近硬球的冻结体积分数，以及对于随机紧密堆积，观察到局部构型的体积分数分布中出现意外的分裂峰。我们的系综分析通过将通过局部规则生成的团簇与随机球体堆积以及包含集体效应的团簇进行比较，突出了随机球体堆积中集体和全局效应的重要性。
