June 28, 2016

Modeling ECD with Real-Time Electronic Dynamics

Different enantiomers of chiral molecules absorb left- and right-handed circularly polarized light differently. This is the physical basis of circular dichroism (CD) spectroscopy, and is one of the most powerful experimental techniques for characterizing enantiomers. Unfortunately, calculating CD spectroscopy is an extremely challenging task. In "An Atomic Orbital Based Real-Time Time-Dependent Density Functional Theory for Computing Electronic Circular Dichroism Band Spectra", we showed how it is possible to extract the CD spectra from the propagation of the time-dependent density functional equations. By perturbing chiral molecules molecules with a weak electric field and tracking the resulting induced magnetic moment in time, we obtained the CD spectrum of several chiral molecules. The advantage of our technique is that we can obtain the whole spectrum in one run, and the method is particularly efficient for large molecules.