Molecular magnetizabilities: Zero-point vibrational effects and the breakdown of Pascal's rule

We demonstrate, by ab initio calculations on more than 60 molecules, that z ero-point vibrational corrections to isotropic magnetizabilities in general are negligible, being less than 0.5% for almost all molecules studied. The exceptions to this rule are aromatic and anti-aromatic ring systems where the effect may be as large as 1% due to a sizable vibrational contribution to the component of the magnetizability perpendicular to the molecular plan e. For the magnetizability anisotropy, zero-point vibrational corrections a re much more important, often contributing 5 - 10% of the total vibrational ly averaged magnetizability anisotropy. We also demonstrate that the additi vity of magnetizabilities (known as Pascal's rule) breaks down in the case of fluorine-containing molecules.