来自蒙特卡洛模拟的水合的度和度
1Department of Chemistry, Yale University, New Haven, Connecticut, 06520-8107, USA. william.jorgensen@yale.edu.
Physical chemistry chemical physics : PCCP
|February 27, 2024
概括
计算水中的有机溶液的溶解热力学现在更加精确. 新的方法改善了和计算,揭示了过多的疏水性是由变化驱动的.
科学领域:
- 物理化学 物理化学
- 计算化学计算化学
- 热力学是一种热力学.
背景情况:
- 溶解热力学 (自由能量,,) 是了解溶解物在溶液中的行为的关键.
- 使用蒙特卡洛 (MC) 和分子动力学 (MD) 模拟来计算溶解的自由能量是常规的.
- 和计算比自由能量计算更具挑战性.
研究的目的:
- 开发和应用精确的方法来计算TIP4P水中中性有机溶液的溶解的和.
- 用广泛的MC模拟来提高热力学溶解计算的准确性.
- 为了调查有机溶液中过度疏水性的起源.
主要方法:
- 采用了自由能量扰动理论与MC模拟.
- 使用两种方法来计算/:直接平均和范特·霍夫 (自由能量的温度导数).
- 进行了广泛的模拟 (5亿个MC配置) 以获得高精度.
主要成果:
- 在水解的自由能量 (0.05 kcal mol−1 不确定性) 中获得了高精度.
- 使用这两种方法,以更高的不确定性 (0.4 kcal mol-1) 计算了度变化.
- 部分摩尔水化量与实验数据有很好的一致性 (3cm3mol-1平均偏差).
结论:
- 该研究为TIP4P水和有机溶液提供了最终的热力学数据.
- OPLS-AA力场的自由能量误差可以分解为体和体组成部分.
- 有机溶液的过度疏水性主要是源于体.
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