Computationally Efficient Polarizable MD Simulations: A Simple Water Model for the Classical Drude Oscillator Polarizable Force Field

An improvement in the computational efficiency of polarizable force field simulations is made through the development of a polarizable Drude water model, SWM3, in combination with the use of Lennard-Jones Particle Mesh Ewald (LJPME) for the treatment of long-range LJ interactions. The experimental bulk properties, density, heat of vaporization, dielectric constant, and self-diffusion constant of the SWM3 model are accurately replicated at ambient condition. The temperature dependence of the bulk properties is also captured except for the density. Microscopic properties, such as hydration free energy, dimer properties, and binding energies of clusters are well represented. The SWM3 model is ∼40% faster than the SWM4 water model traditionally used with the Drude force field, and use of LJPME offers an additional 30% speedup in heterogeneous systems. This combination makes the SWM3-based Drude model only 2.6-fold slower than the TIP3P-based additive simulations.