Theory Department
Max Planck Institute of Microstructure Physics
1997    
1998    
1999    
2000    
2001    
2002    
2003    
2004    
2005    
2006    
2007    
2008    
2009    
2010    
2011    
2012    
2013    
2014    
2015    
2016    
2017    
2018    
2019    
2020    
2021    
Scherrer, A., Agostini, F., Sebastiani, D., Gross, E. K. U., Vuilleumier, R.

Nuclear velocity perturbation theory for vibrational circular dichroism: An approach based on the exact factorization of the electron-nuclear wave function
Journal of Chemical Physics 143, (7),pp 074106/1-12 (2015)
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.

TH-2015-29