Subject dynamic imaging

When observed structure factors are used, the thermally averaged deformation density, often labeled the dynamic deformation density, is obtained. An attractive alternative is to replace the observed structure factors in Eq. (5.8) by those calculated with the multipole model. The resulting dynamic model deformation map is model dependent, but any noise not fitted by the muitipole functions will be eliminated. It is also possible to plot the model density directly using the model functions and the experimental charge density parameters. In that case, thermal motion can be eliminated (subject to the approximations of the thermal motion formalism ), and an image of the static model deformation density is obtained, as discussed further in section 5.2.4. 

Fig. 21 STM simulations for systems subject to a static vs. dynamic JT effect. The top row corresponds to the excited state and the bottom to the ground state. In (a), infinitely strong coupling locks the molecule into one particular well. Finite but strong coupling (so that the system jumps between three wells) is shown in (b). Further reduction in localisation leads to essentially free pseudorotation, producing the time-averaged images in (c)...

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