Uncoupled Hartree–Fock perturbation theory is used to compute the ring-current contributions to the magnetic susceptibilities of several conjugated hydrocarbons. In the usual form of the perturbation theory this leads to an origin dependent result, but when corrections are included this origin dependence is removed. The final results agree very well with those calculated using the more complicated coupled Hartree–Fock method, and, when empirical values are used for the local contributions to the susceptibility, the theoretical values for the components, the mean value, and the anisotropy of the susceptibility are in excellent agreement with experiment.

Within the context of pi-electron theory an expression for the proton chemical shifts in conjugated molecules is derived via a current density approach. Using London integral approximations the method is applied to benzene and naphthalene. Provided a particular form of the London Approximation is used, theoretical values in good agreement with experiment are obtained.

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