T - IfB

Particle – Mesh algorithmJ.W. Eastwood, R.W. Hockney and D.N.Lawrence (1980)• Put a fine mesh on top of the system (M ≈ N).• Distribute the charges onto the mesh points.• Calculate electrostatic potential by solving thePoisson equation on the mesh using FFT.• Calculate force on each particle by numericallydifferentiating the potential and interpolatingback from the mesh to the particle position.101Particle – Mesh algorithmCriteria for a good PM scheme:• Errors should vanish at large particledistances. • Momentum conservation: Fij=-Fji• Charges on mesh and interpolatedforces should vary smoothly withparticle position.102