论文标题
热力学表面阶段的初始方法，并充分考虑了Anharmonic效应 - SI氢的例子（100）
Ab initio approach for thermodynamic surface phases with full consideration of anharmonic effects -- the example of hydrogen at Si(100)
论文作者
论文摘要
反应性环境中表面结构的可靠描述对于理解材料功能至关重要。我们提出了第一个原理理论的复制 - 交换大型民用分子动力学（REGC-MD），并将其应用于反应性气相环境中表面的相位平衡。我们确定不同的表面阶段，并找到包括三重和临界点在内的相边界。通过解决与氢气大气接触的SI（100）表面的开放问题来证明该方法。在300至1000 K的范围内，我们发现25个不同的热力学稳定表面相，我们还提供了微观描述。尚未通过实验观察到大多数确定的阶段，包括很少的订单阶相跃迁。 REGC-MD衍生的相图显示了最先进的“从头开始原子热力学”方法对描述的显着质量差异。
A reliable description of surfaces structures in a reactive environment is crucial to understand materials functions. We present a first-principles theory of replica-exchange grand-canonical-ensemble molecular dynamics (REGC-MD) and apply it to evaluate phase equilibria of surfaces in reactive gas-phase environment. We identify the different surface phases and locate phase boundaries including triple and critical points. The approach is demonstrated by addressing open questions for the Si(100) surface in contact with a hydrogen atmosphere. In the range from 300 to 1 000 K, we find 25 distinct thermodynamically stable surface phases, for which we also provide microscopic descriptions. Most of the identified phases, including few order-disorder phase transitions, have not yet been observed experimentally. The REGC-MD-derived phase diagram shows significant, qualitative differences to the description by the state-of-the-art "ab initio atomistic thermodynamics" approach.
