Optical rotation (OR) refers to the phenomenon of rotation of the plane of polarization of impinging linearly polarized light by an optically active sample, e.g., a sample with an enantiomeric excess of a chiral compound. The ubiquity of enantiospecific chiral molecules in biological systems makes the ability to differentiate enantiomers especially relevant. While experimental measurements can provide the sign and magnitude of the rotation, theoretical simulations are necessary to correlate the sign of the rotation to the structure of the molecule. Therefore, the assignment of the absolute configuration of a chiral sample requires a synergistic effort of experiment and theory.