AI 中文总结
研究针对模拟崎岖自由能景观系统的挑战，提出超空间副本交换（HS - REX）方法，通过额外维度扩展系统以规避障碍，仅惩罚溶质原子减少副本数，在双阱和丙氨酸二肽系统验证，实现增强遍历采样。
AI 中文摘要
在计算物理和化学中，模拟具有崎岖自由能景观的系统仍然是一个核心挑战。我们引入了超空间副本交换（HS - REX），这是一种增强采样方法，通过额外的空间维度人为扩展物理系统。在更高维度中，可通过原始空间中几何上不可达的路径规避自由能障碍。与标准温度副本交换相比，仅对溶质原子施加惩罚极大减少了溶剂化系统所需的副本数量，这对生物应用尤为重要。作为概念验证，我们在双阱模型系统和明确水中的丙氨酸二肽基准系统上展示了该方法。在后者中，HS - REX不仅实现了对缓慢的主链二面角的增强构象采样，还实现了分子的两种手性构型的采样，而这在三维标准采样中是空间不可达的。这证明了相对于传统温度副本交换的增强遍历采样。
英文摘要
Simulating systems with rugged free-energy landscapes remains a central challenge in computational physics and chemistry. We introduce hyperspatial replica exchange (HS-REX), an enhanced sampling method in which the physical system is artificially extended by additional spatial dimensions. In higher dimensions, free-energy barriers can be circumvented through paths that are geometrically inaccessible in the original space. Restricting the penalty to only solute atoms dramatically reduces the number of replicas required for solvated systems compared to standard temperature replica exchange, a feature especially relevant for biological applications. As proof of concept, we demonstrate the method on a double-well model system and on alanine dipeptide in explicit water as benchmark system. In the latter case, HS-REX achieves enhanced conformational sampling of not only the slow backbone dihedral angles, but also both chiral configurations of the molecule, which are sterically inaccessible to standard sampling in three dimensions. This demonstrates enhanced ergodic sampling over conventional temperature replica exchange.
