New Estimators for Calculating Solvation Entropy and Enthalpy and Comparative Assessments of Their Accuracy and Precision

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• 作者：Matthew A. Wyczalkowski ; Andreas Vitalis ; Rohit V. Pappu
• 刊名：Journal of Physical Chemistry B
• 出版年：2010
• 出版时间：June 24, 2010
• 年：2010
• 卷：114
• 期：24
• 页码：8166-8180
• 全文大小：589K
• 年卷期：v.114,no.24(June 24, 2010)
• ISSN：1520-5207

文摘

We present two new methods for estimating the entropy and enthalpy decomposition of free energy calculations. These methods are based on temperature derivatives of the Bennett Acceptance Ratio and the Multistate Bennett Acceptance Ratio estimators, respectively. We test the accuracy of these new estimators using a simple one-dimensional model. A detailed assessment of their performance is reported by studying the solvation of N-methylacetamide. Finally, we quantify the free energies of solvation for 11 model compounds using the OPLS-AA force field and a variation of this force field. Thermodynamic decompositions of these calculated free energies are obtained to highlight the utility of these quantities for refining force field parameters by comparing computed free energies and their decompositions to their experimental counterparts.