Melting presents one of the most prominent phenomena in condensed matter science. Its microscopic understanding, however, is still fragmented, ranging from simplistic theory to the observation of melting point depressions. Here, a multimethod experimental approach is combined with computational simulation to study the microscopic mechanism of melting between these two extremes. Crystalline structures are exploited in which melting occurs into a metastable liquid close to its glass transition temperature. The associated sluggish dynamics concur with real‐time observation of homogeneous melting. In‐depth information on the structural signature is obtained from various independent spectroscopic and scattering methods, revealing a step‐wise nature of the transition before reaching the liquid state. A kinetic model is derived in which the first reaction step is promoted by local instability events, and the second is driven by diffusive mobility. Computational simulation provides further confirmation for the sequential reaction steps and for the details of the associated structural dynamics. The successful quantitative modeling of the low‐temperature decelerated melting of zeolite crystals, reconciling homogeneous with heterogeneous processes, should serve as a platform for understanding the inherent instability of other zeolitic structures, as well as the prolific and more complex nanoporous metal–organic frameworks.

中文翻译：

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减速熔融动力学

融化是凝聚态科学中最突出的现象之一。但是，从微观理论到对熔点降低的观察，对微观的理解仍然是零散的。在这里，将一种多方法实验方法与计算仿真相结合，以研究这两个极端之间融化的微观机制。利用晶体结构，其中熔融发生在接近其玻璃化转变温度的亚稳态液体中。相关的迟缓动力学与实时均匀熔体观察一致。可通过各种独立的光谱和散射方法获得有关结构特征的深入信息，从而揭示了过渡态在达到液态之前的逐步性质。得出动力学模型，其中第一反应步骤由局部不稳定性事件促进，第二反应步骤由扩散迁移率驱动。计算仿真为顺序反应步骤以及相关结构动力学的细节提供了进一步的确认。沸石晶体低温减速熔融的成功定量建模，使均相与异质过程协调一致，应成为理解其他沸石结构固有的不稳定性以及多产且更复杂的纳米多孔金属有机框架的平台。计算模拟为顺序反应步骤以及相关结构动力学的细节提供了进一步的确认。沸石晶体低温减速熔融的成功定量建模，使均相与异质过程协调一致，应成为理解其他沸石结构固有的不稳定性以及多产且更复杂的纳米多孔金属有机框架的平台。计算模拟为顺序反应步骤以及相关结构动力学的细节提供了进一步的确认。沸石晶体低温减速熔融的成功定量建模，使均相与异质过程协调一致，应成为理解其他沸石结构固有的不稳定性以及多产且更复杂的纳米多孔金属有机框架的平台。