  A deformable body can rotate even with no angular momentum, simply by
changing its shape. A good example is a falling cat, how it maneuvers in air to
land on its feet. Here a first principles molecular level example of the
phenomenon is presented. For this the thermal vibrations of individual atoms in
an isolated cyclopropane molecule are simulated in vacuum and at ultralow
internal temperature values, and the ensuing molecular motion is followed
stroboscopically. It is observed that in the limit of long stroboscopic time
steps the vibrations combine into an apparent uniform rotation of the entire
molecule even in the absence of angular momentum. This large time scale
rotational motion is then modeled in an effective theory approach, in terms of
timecrystalline Hamiltonian dynamics. The phenomenon is a temperature sensitive
measurable. As such it has potential applications that range from models of
autonomous molecular motors to development of molecular level detector, sensor
and control technologies.
