  Diffraction experiments have moved to ever heavier objects in recent years,
now standing at the level of large molecules. Experiments in materials science
on the other hand have come down to ever smaller sizes largely due to the
success of the scanning tunneling microscope (STM), which allows studying
single molecules on surfaces. Since both fields coming from opposite side of
the size spectrum are now meeting, there is a need of consistent theories. The
simulations presented in the article, which we are referring to, are not
consistent with molecular dynamics simulations which are routinely used to
interpret STM results. Our comment points this out in detail.
