Ewald summation is a method used to calculate long-range interactions in materials simulations, such as electrostatic and van der Waals forces. It was developed by Paul Ewald in 1921 and is commonly used in molecular dynamics simulations.
Materials simulations often involve large systems with many particles, which can create long-range interactions that are difficult to calculate accurately. Ewald summation allows for an efficient and accurate calculation of these interactions, making it a valuable tool in materials research.
Ewald summation uses a combination of real and reciprocal space calculations to accurately calculate long-range interactions. The real space calculation accounts for interactions between nearby particles, while the reciprocal space calculation takes into account interactions between particles that are further away.
Ewald summation is commonly used in simulations of ionic systems, such as salts and polymers, as well as systems with charged particles. It can also be applied to simulations of non-ionic systems, such as molecular liquids, by treating the non-ionic interactions as a screened Coulomb potential.
Ewald summation can be computationally expensive for large systems, as it requires both real and reciprocal space calculations. Additionally, it may not be suitable for systems with highly anisotropic interactions or systems with a large number of charged particles. Alternative methods, such as particle-mesh Ewald summation, have been developed to overcome some of these limitations.