If the hyperfine field fluctuates during the lifetime τ τ n of the intermediate level due to jumps of the probe into another lattice position or from jumps of a near atom into another lattice position, the correlation is lost. For the simple case with an undistorted lattice of cubic symmetry, for a jump rate of ω ω s < 0.2 ⋅ ⋅ ν ν Q for equivalent places N s , an exponential damping of the static G 22 ( t ) -terms is observed: