标题： 解读星际冰形态：原子模拟揭示乙硫醇的复杂行为 显示英文标题

标题： Deciphering Interstellar Ice Morphology: Atomistic Simulations Reveal the Complex Behavior of Ethanethiol

摘要： 乙硫醇（C$_2$H$_5$SH）是一种在星际介质（ISM）中被检测到的分子，表明了涉及硫原子的丰富化学反应。然而，其在低温下的行为仍不清楚，尤其是从非晶态转变为晶体的报道转变。本研究使用经典分子动力学（MD）模拟来重现乙硫醇的液态性质，并模拟沉积在溴化钾基底上的乙硫醇薄膜的初始非晶态。非晶态乙硫醇在温度升高时并未显示出自发结晶现象。此外，在溴化钾基底上，乙硫醇冰晶体表现出在高温下的熔融行为。我们对薄冰样品的MD模拟没有发现任何可逆相变的特征。继续用更厚的样品进行这项研究将非常有趣，但超出了我们目前的计算能力。这些发现强调了冷星际介质尘埃颗粒上冰质包层形态的复杂性。 显示英文摘要

摘要： Ethanethiol (C$_2$H$_5$SH), a molecule detected in the interstellar medium (ISM), indicates the rich chemistry involving sulfur atoms. However, its behavior at low temperatures remains elusive, particularly the reported transition from an amorphous phase to a crystal. This study employs classical molecular dynamics (MD) simulations to reproduce the liquid-state properties of ethanethiol and to simulate the initial amorphous state of ethanethiol films deposited on a KBr substrate. The amorphous ethanethiol did not show spontaneous crystallization upon increasing temperature. Also, ethanethiol ice crystals exhibit melting behavior on KBr substrate at elevated temperatures. Our MD simulations of thin ice samples do not show any signature reversible phase change. It will be interesting to continue this study with a thicker sample, which is beyond our current computational means. These findings underscore the complexity of icy mantle morphology on cold ISM dust grains.