MAGNETIZABILITY OF HYDROCARBONS

The magnetizability of a large number of hydrocarbons-saturated, unsat urated, and aromatic-have been investigated by ab initio methods at th e Hartree-Fock level. Gauge-origin independence and size extensivity a re imposed by the use of London atomic orbitals (also known as gauge-i nvariant atomic orbitals). Using a standard basis set adapted for magn etizabilities, results close to the Hartree-Fock limit are obtained. C orrelation has a moderate effect on the magnetizabilities. Using an ov erall scaling factor for the Hartree-Fock results, we obtain magnetiza bilities within the experimental error bars for most of the molecules considered. The calculations suggest that the observed gas-phase magne tizabilities contain a calibration error.