In this year we devoted extensive effort to the development of improved force fields that can interface seamlessly with quantum chemical methods, in particular Density Functional Theory, to study the reaction mechanisms HIV-1 macromolecules. Due to the high concentration of charged amino acid and nucleic acid residues, as well as the presence of metal ions, the treatment of short ranged and long ranged electrostatics is critical to achieving reliable results. We are continued an effort to develop an all-atom model for the HIV-1 Integrase system, for which structural information has became available within the past several years.