In condensed matter physics, the dynamic structure factor is a mathematical function that contains information about inter-particle correlations and their time evolution. It is a generalization of the structure factor which considers correlations in both space and time. Experimentally, it can be accessed most directly by inelastic neutron scattering.
The dynamic structure factor is most often denoted
Here
Thus we see that the dynamical structure factor is the spatial and temporal Fourier transform of van Hove's time-dependent pair correlation function. It can be shown (see below), that the intermediate scattering function is the correlation function of the Fourier components of the density
The dynamic structure is exactly what is probed in coherent inelastic neutron scattering. The differential cross section is :
where
The van Hove Function
The van Hove Function for a spatially uniform system containing
It can be rewritten as:
In an isotropic sample (with scalar r), G(r,t) is a time dependent radial distribution function.