Can Induced Orbital Paramagnetism Be Controlled by Strong Magnetic Fields?

Magnetic hypersusceptibilities and hypershielding at the nuclei of BH, CH(+), C4H4, and C8H8 molecules in the presence of an external spatially uniform, time-independent magnetic field have been investigated accounting for cubic response contributions via Rayleigh-Schrödinger perturbation theory. Numerical estimates have been obtained at the coupled Hartree-Fock and density-functional levels of theory within the conventional common-origin approach, using extended gaugeless basis sets. The fundamental role of electron correlation effects was assessed. Critical values of the applied magnetic field at which transition from paramagnetic to diamagnetic behavior would occur were estimated. It is shown that perturbative methods may successfully be employed to estimate the interaction energy for big cyclic molecules.