Molecular dynamics simulations often adopt coarse-grained (CG) models to investigate length- and time-scales that cannot be effectively addressed with atomically detailed models. However, the effective potentials that govern CG models are configuration-dependent free energies with significant entropic contributions that have important consequences for the transferability and thermodynamic properties of CG models. This review summarizes recent work investigating the fundamental origin and practical ramifications of these entropic contributions, as well as their sensitivity to the CG mapping. We first analyze the energetic and entropic components of the many-body potential of mean force. By adopting a simple model for protein fluctuations, we examine how these components vary with the CG representation. We then introduce a “dual potential” approach for addressing these entropic considerations in more complex systems, such as ortho-terphenyl (OTP). We demonstrate that this dual approach not only accurately describes the structure and energetic properties of the underlying atomic model, but also accurately predicts the temperature-dependence of the CG potentials. Furthermore, by considering two different CG representations of OTP, we elucidate how these contributions vary with resolution. In sum, we hope this work will prove useful for improving the transferability and thermodynamic properties of CG models for soft materials.

分子动力学模拟通常采用粗粒度 (CG) 模型来研究无法用原子级详细模型有效解决的长度和时间尺度。然而，控制 CG 模型的有效势是依赖于配置的自由能，具有显着的熵贡献，对 CG 模型的可转移性和热力学性质具有重要影响。这篇综述总结了最近的工作，这些工作调查了这些熵贡献的基本起源和实际后果，以及它们对 CG 映射的敏感性。我们首先分析平均力的多体势的能量和熵分量。通过采用简单的蛋白质波动模型，我们研究了这些成分如何随 CG 表示而变化。然后，我们引入了一种“双势”方法来解决更复杂系统中的这些熵问题，例如邻三联苯 (OTP)。我们证明这种双重方法不仅准确地描述了基础原子模型的结构和能量特性，而且还准确地预测了 CG 势的温度依赖性。此外，通过考虑 OTP 的两种不同 CG 表示，我们阐明了这些贡献如何随分辨率变化。总之，我们希望这项工作对提高软材料 CG 模型的可转移性和热力学性能有用。我们证明这种双重方法不仅准确地描述了基础原子模型的结构和能量特性，而且还准确地预测了 CG 势的温度依赖性。此外，通过考虑 OTP 的两种不同 CG 表示，我们阐明了这些贡献如何随分辨率变化。总之，我们希望这项工作对提高软材料 CG 模型的可转移性和热力学性能有用。我们证明这种双重方法不仅准确地描述了基础原子模型的结构和能量特性，而且还准确地预测了 CG 势的温度依赖性。此外，通过考虑 OTP 的两种不同 CG 表示，我们阐明了这些贡献如何随分辨率变化。总之，我们希望这项工作对提高软材料 CG 模型的可转移性和热力学性能有用。