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Computational methodology for solubility prediction: Application to the sparingly soluble solutes

Published version
Peer-reviewed

Type

Article

Change log

Authors

Li, L 
Totton, T 

Abstract

The solubility of a crystalline substance in the solution can be estimated from its absolute solid free energy and excess solvation free energy. Here, we present a numerical method, which enables convenient solubility estimation of general molecular crystals at arbitrary thermodynamic conditions where solid and solution can coexist. The methodology is based on standard alchemical free energy methods, such as thermodynamic integration and free energy perturbation, and consists of two parts: (1) systematic extension of the Einstein crystal method to calculate the absolute solid free energies of molecular crystals at arbitrary temperatures and pressures and (2) a flexible cavity method that can yield accurate estimates of the excess solvation free energies. As an illustration, via classical Molecular Dynamic simulations, we show that our approach can predict the solubility of OPLS-AA-based (Optimized Potentials for Liquid Simulations All Atomic) naphthalene in SPC (Simple Point Charge) water in good agreement with experimental data at various temperatures and pressures. Because the procedure is simple and general and only makes use of readily available open-source software, the methodology should provide a powerful tool for universal solubility prediction.

Description

Keywords

0307 Theoretical and Computational Chemistry, 0306 Physical Chemistry (incl. Structural)

Journal Title

Journal of Chemical Physics

Conference Name

Journal ISSN

0021-9606
1089-7690

Volume Title

146

Publisher

AIP Publishing
Sponsorship
The authors would like to acknowledge the funding and technical support including BP’s High Performance Computing facility, from BP through the BP International Centre for Advanced Materials (BP-ICAM) which made this research possible. All the simulations in the work were hence conducted using the HPC resources from BP and computer resources at the Department of Chemistry, Cambridge.