Acceleration of convergence for lattice sums

The lattice sums of nonbond interactions (electrostatic and dispersion) for computer simulations of periodic systems typically coverge very slowly. Here, we examine the accelerated convergence of these sums based on Ewald procedures and derive equations for the energies, forces, stresses, and curvatures. A method is proposed and tested for selecting the convergence acceleration parameter η on the basis of minimum calculation time. As an illustration and check, the properties of argon and NaCl crystals are calculated by using these equations and compared with values obtained analytically.