title: Origin-independent sum over states simulations of magnetic and electronic circular dichroism spectra via the localized orbital/local origin method.
abstract: Although electronic and magnetic circular dichroism (ECD, MCD) spectra reveal valuable details about molecular geometry and electronic structure, quantum-chemical simulations significantly facilitate their interpretation. However, the simulated results may depend on the choice of coordinate origin. Previously (Štěpánek and Bouř, J. Comput. Chem. 2013, 34, 1531), the sum-over-states (SOS) methodology was found useful for efficient MCD computations. Approximate wave functions were "resolved" using time-dependent density functional theory, and the origin-dependence was avoided by placing the origin to the center of mass of the investigated molecule. In this study, a more elegant way is proposed, based on the localized orbital/local origin (LORG) formalism, and a similar approach is also applied to generate ECD intensities. The LORG-like approach yields fully origin-independent ECD and MCD spectra. The results thus indicate that the computationally relatively cheap SOS simulations open a new way of modeling molecular properties, including those involving the origin-dependent magnetic dipole moment operator.
authors: Group of Molecular Spectroscopy, Institute of Organic Chemistry and Biochemistry, Academy of Sciences, Flemingovo nám. 2, 16610, Prague, Czech Republic; Institute of Physics, Faculty of Mathematics and Physics, Charles University, Ke Karlovu 5, 121 16, Prague, Czech Republic.
authors: Petr
authors: P
authors: Štěpánek
authors: Petr
authors: P
authors: Bouř
keywords: density functional theory; electronic circular dichroism; magnetic circular dichroism; origin-dependence