title: Nuclear velocity perturbation theory for vibrational circular dichroism: An approach based on the exact factorization of the electron-nuclear wave function.
abstract: The nuclear velocity perturbation theory (NVPT) for vibrational circular dichroism (VCD) is derived from the exact factorization of the electron-nuclear wave function. This new formalism offers an exact starting point to include correction terms to the Born-Oppenheimer (BO) form of the molecular wave function, similar to the complete-adiabatic approximation. The corrections depend on a small parameter that, in a classical treatment of the nuclei, is identified as the nuclear velocity. Apart from proposing a rigorous basis for the NVPT, we show that the rotational strengths, related to the intensity of the VCD signal, contain a new contribution beyond-BO that can be evaluated with the NVPT and that only arises when the exact factorization approach is employed. Numerical results are presented for chiral and non-chiral systems to test the validity of the approach.
authors: Martin-Luther-University Halle-Wittenberg, von-Danckelmann-Platz 4, D-06120 Halle, Germany.
authors: Arne
authors: A
authors: Scherrer
authors: Max-Planck-Institute of Microstructure Physics, Weinberg 2, D-06120 Halle, Germany.
authors: Federica
authors: F
authors: Agostini
authors: Martin-Luther-University Halle-Wittenberg, von-Danckelmann-Platz 4, D-06120 Halle, Germany.
authors: Daniel
authors: D
authors: Sebastiani
authors: Max-Planck-Institute of Microstructure Physics, Weinberg 2, D-06120 Halle, Germany.
authors: E K U
authors: EK
authors: Gross
authors: UMR 8640 ENS-CNRS-UPMC, Département de Chimie, 24 rue Lhomond, École Normale Supérieure, 75005 Paris, France.
authors: Rodolphe
authors: R
authors: Vuilleumier