Simulating Picosecond X-ray Diffraction from Shocked Crystals using FFT Methods on MD Output

Multi-million atom non-equilibrium molecular dynamics (MD) simulations give significant insight into the transient processes that occur under shock compression. Pico-second X-ray diffraction enables the probing of materials on a timescale fast enough to test such effects. In order to simulate diffraction patterns, Fourier methods are required to gain a picture of reciprocal lattice space. We present here results of fast Fourier transforms of atomic coordinates of shocked crystals simulated by MD, and comment on the computing power required as a function of problem size. The relationship between reciprocal space and particular experimental geometries is discussed.