An efficient technique for the prediction of solvent-dependent morphology: the COSMIC method

Abstract

We have developed a method of calculating the solvation energy of a surface based on an implicit solvent model. This new model called COSMIC, is an extension of the established COSMO solvation approach and allows the technique to be applied to systems of any periodicity from finite molecules, through polymers and surfaces, to cavities of water within a bulk unit cell. As well as extending the scope of the COSMO technique, it also improves the numerical stability through removal of a number of discontinuities in the potential energy surface. The COSMIC model has been applied to barium sulfate, where it was found to produce similar surface energies and configurations to the much more computationally expensive explicit molecular dynamics simulations. The calculated solvated morphology of barium sulfate was found to differ significantly to that calculated in vacuum with a reduced number of faces present.

Keywords:

• Solvation
• Surface energy
• Barium sulfate
• COSMO

Acknowledgements

We gratefully acknowledge the initial support of this work through funding from the Australian Research Council under IREX grant no. X00106744. JDG would also like to thank the Government of Western Australia for a Premier's Research Fellowship. Dr Stefano Piana is gratefully acknowledged for valuable discussions. We would like to thank iVEC and APAC for the provision of computing resources.