A New Approach for Estimating the Free Energy Differences among Multiple Thermodynamic States in Statistical Simulations.
A New Approach for Estimating the Free Energy Differences among Multiple Thermodynamic States in Statistical Simulations.
复制标题
估计统计模拟中多个热力学状态之间的自由能差异的新方法。
DOI：
10.1021/acs.jpclett.3c00620
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发表时间：
2023
期刊：
影响因子：
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通讯作者：
Singer,SherwinJ
中科院分区：
文献类型：
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作者：
Yang,Jaehoon;Singer,SherwinJ
在这封信中，介绍了一种新的方法来计算多个热力学状态之间的自由能差（FED）。该方法直接使用能量概率密度，它可以从平衡模拟中以高精度提取，以获得FED。目前使用的方法，如班尼特接受比（BAR），其多态推广（MBAR），或加权直方图分析方法（WHAM），需要迭代求解的非线性方程，已知是缓慢收敛。提供MBAR FED的方程与Souaille和Roux先前以非正式地称为“无箱WHAM”的方法导出的方程相同。相反，我们通过线性方程组的解获得FED。对于经典的两状态问题，我们的方法，求解线性方程组的统计误差，分析显示，在一般条件下匹配BAR。
In this letter, a new approach to compute free energy differences (FEDs) between multiple thermodynamics states is introduced. The method directly uses energy probability densities, which can be extracted with high accuracy from equilibrium simulations to obtain FEDs. Methods in current use, such as Bennett acceptance ratio (BAR), its multistate generalization (MBAR), or the weighted histogram analysis method (WHAM), require iterative solution of nonlinear equations which are known to be slowly convergent. The equations providing MBAR FEDs are identical to those derived earlier by Souaille and Roux in a method that has become known informally as “binless WHAM”. In contrast, we obtain FEDs by solution of linear equations. For the classic two-state problem, the statistical error of our method, solving linear equations, is shown analytically to match that of BAR under common conditions.