Comparing Alchemical Free Energy Estimates to Experimental Values Based on the Ben-Naim Formula: How Much Agreement Can We Expect?
Comparing Alchemical Free Energy Estimates to Experimental Values Based on the Ben-Naim Formula: How Much Agreement Can We Expect?
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DOI：
10.1021/acs.jpcb.9b08965
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发表时间：
2020-02-06
期刊：
影响因子：
--
通讯作者：
Wang F
中科院分区：
文献类型：
--
作者：
Rogers TR;Wang F
溶剂化自由能在热力学中起着重要的作用。一种行之有效的计算超临界流体能量的方法是通过炼金术转化。然而，实验SFE通常根据本-纳伊姆方程依赖于蒸汽压或密度比来确定。重要的是要确定是否，或在何种程度上，典型的基于化学的自由能计算提供的结果与实验SFE。在这项工作中，我们模仿实验测量模拟水的液体-蒸汽共存没有炼金术的操作。通过蒸汽压和密度比测量的SFE被用来验证通过炼金术转换获得的SFE。结果表明，适当考虑蒸汽的非理想行为是很重要的，以确保炼金术的SFE是一致的Ben-Naim SFE。对于强相互作用的溶质，例如具有低沸点温度和大的第二维里系数的溶质，除了溶液相变之外，还应该进行气相中的炼金术相变。提出了一个基于压力维里展开的公式，以便从模拟的蒸汽压中更好地估计真实的SFE。建议的公式也适用于实验测定超临界流体时，压力为基础的路线。
The solvation free energy (SFE) plays a key role in thermodynamics. One well-established method for computing the SFE is through an alchemical transformation. However, experimental SFEs are generally determined according to the Ben-Naim equations relying on vapor pressure or density ratios. It is important to establish whether, or to what extent, typical alchemical-based free energy computations provide results comparable to experimental SFEs. In this work, we mimic experimental measurements by simulating the liquid–vapor coexistence of water without alchemical operations. The SFEs measured through vapor pressure and density ratios are used to validate the SFEs obtained through alchemical transformations. It is shown that proper consideration of the nonideal behavior of the vapor is important to ensure that the alchemical SFEs are consistent with the Ben-Naim SFEs. Alchemical transformations in the vapor phase should be performed in addition to solution phase transformations for strongly interacting solutes, such as those with low boiling temperatures and large second virial coefficients. A formula based on the virial expansion of pressure is proposed to provide a better estimate of the true SFE from the simulated vapor pressures. The proposed formula is also applicable to experimental determinations of SFE when the pressure-based route is used.
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影响因子：
4.1
作者：
BENNETT, CH
通讯作者：
BENNETT, CH
影响因子：
15
作者：
Hamelberg, D;McCammon, JA
通讯作者：
McCammon, JA
影响因子：
2.6
作者：
EUBANK, PT;JOFFRION, LL;WAROWNY, W
通讯作者：
WAROWNY, W
影响因子：
4.4
作者：
BENNAIM, A;MARCUS, Y
通讯作者：
MARCUS, Y
影响因子：
2.9
作者：
HOOVER, WG
通讯作者：
HOOVER, WG