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)₈²⁺ 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.