The MSXX force field for the barium sulfate-water interface

A new force field (MSXX FF) was developed for barium sulfate (BaSO4) to reproduce the experimental properties of BaSO4 crystal (density, lattice energy, compressibility, and vibrational spectrum) and to describe properly the interaction between BaSO4 and water (binding energies and interatomic distances of Ba(H2O)(8)(2+) and (SO4)(H2O)(6)(2-) clusters determined from ab initio quantum mechanics calculations). Using this FF in combination with F3C FF for water, the surface energies for several surfaces of BaSO4 were examined both in a vacuum and in the presence of an explicit water bath in contact with them. The same level of FF's are also reported for CaSO4 and SrSO4.