Tripodo Antonio, Puosi Francesco, Malvaldi Marco, Leporini Dino
Dipartimento di Fisica "Enrico Fermi", Università di Pisa, Largo B. Pontecorvo 3, I-56127, Pisa, Italy.
IPCF-CNR, UOS, Pisa, Italy.
Eur Phys J E Soft Matter. 2019 Nov 22;42(11):146. doi: 10.1140/epje/i2019-11916-6.
The correlations detected by the mutual information in the propensities of a molecular viscous liquid are studied by molecular-dynamics simulations. Dynamic heterogeneity is evidenced and two particle fractions with different mobility and relaxation identified. The two fractions exhibit the scaling of their relaxation in terms of the rattling amplitude of the particle trapped in the cage of the first neighbours 〈u〉 . The scaling master curve does not differ from the one found for bulk systems, thus confirming identical results previously reported in other systems with strong dynamic heterogeneity as thin molecular films. The excitation of planar and globular structures at short and long times with respect to structural relaxation, respectively, is revealed. Some of the globular structures are different from the ones evidenced in atomic mixtures. States with equal 〈u〉 are found to have identical time dependence of several quantities, referring to both bulk and the two fractions with heterogeneous dynamics, at least up to the structural relaxation time [Formula: see text].
通过分子动力学模拟研究了分子粘性液体倾向中互信息检测到的相关性。证实了动态非均匀性，并识别出具有不同迁移率和弛豫的两个粒子部分。这两个部分根据被困在第一近邻笼子中的粒子的晃动幅度〈u〉表现出它们弛豫的标度关系。标度主曲线与在体系统中发现的曲线没有差异，从而证实了先前在其他具有强动态非均匀性的系统（如薄分子膜）中报道的相同结果。分别揭示了相对于结构弛豫在短时间和长时间激发的平面和球状结构。一些球状结构与原子混合物中证实的结构不同。发现具有相等〈u〉的状态对于几个量具有相同的时间依赖性，这涉及体相以及具有非均匀动力学的两个部分，至少直到结构弛豫时间[公式：见正文]。
