Calculation of the ℬ term of magnetic circular dichroism. A time-dependent density functional theory approach

A method for calculating the ℬ term of magnetic circular dichroism utilizing time-dependent density functional theory is presented. The expression for the ℬ term is formulated through the standard sum-over-states approach, and all necessary matrix elements and transition energies are provided by the time-dependent density functional theory calculation. Test calculations of the magnetic circular dichroism spectra of ethene, propene, furan and its heavier homologues, and pyrrole and two of its derivatives are presented. The discrepancy between theory and experiment previously observed for ethene is not resolved, but the experimental spectra of the aromatic compounds are very well reproduced by the theory.