Flux-side correlation function (source code)

= Flux-side correlation function
{title2=$C_{fs}(t)$}

A time correlation $C_{fs}(t)=\langle\delta(s_0)\dot s_0\Theta(s_t)\rangle$ correlating signed initial flux through a <dividing surface> with product-side occupation at a later time. Dividing by reactant population gives a rate on a plateau after microscopic recrossing and before macroscopic equilibration.