title: Thermodynamics of surface defects at the aspirin/water interface.
abstract: We present a simulation scheme to calculate defect formation free energies at a molecular crystal/water interface based on force-field molecular dynamics simulations. To this end, we adopt and modify existing approaches to calculate binding free energies of biological ligand/receptor complexes to be applicable to common surface defects, such as step edges and kink sites. We obtain statistically accurate and reliable free energy values for the aspirin/water interface, which can be applied to estimate the distribution of defects using well-established thermodynamic relations. As a show case we calculate the free energy upon dissolving molecules from kink sites at the interface. This free energy can be related to the solubility concentration and we obtain solubility values in excellent agreement with experimental results.
authors.affiliation: Chair for Theoretical Chemistry and Catalysis Research Center, Technische Universität München, Lichtenbergstr. 4, D-85747 Garching, Germany.
authors.forename: Julian
authors.initials: J
authors.lastname: Schneider
authors.affiliation: Chair for Theoretical Chemistry and Catalysis Research Center, Technische Universität München, Lichtenbergstr. 4, D-85747 Garching, Germany.
authors.forename: Chen
authors.initials: C
authors.lastname: Zheng
authors.affiliation: Chair for Theoretical Chemistry and Catalysis Research Center, Technische Universität München, Lichtenbergstr. 4, D-85747 Garching, Germany.
authors.forename: Karsten
authors.initials: K
authors.lastname: Reuter
mesh_terms: D000465:Algorithms; D001241:Aspirin / Q000737:chemistry*; D019281:Dimerization; D056004:Molecular Dynamics Simulation; D012997:Solvents / Q000737:chemistry; D013816:Thermodynamics; D014867:Water / Q000737:chemistry*
chemical_list: D012997:Solvents; D014867:Water; D001241:Aspirin