A second effect of the anisotropic polarizability is that it creates a potential barrier for the rotation, i.e., the rotation of the molecule becomes hindered. For TCNE, once again we find that this hindrance is negligible at relevant temperatures, as shown in the Supporting Information. Therefore, we continue to use the ideal gas model for the rotational degrees of freedom: µ rot gas (p, , F ) ≈ µ rot ideal (p, T ). However, also here, for molecules with larger, more anisotropic polarizabilities, this term can become significant.