Photoinduced nonadiabatic dynamics of ethene: Six-dimensional wave packet propagations using two different approximations of the kinetic energy operator

The nonadiabatic dynamics of ethene in its N, V and Z valence states is reinvestigated. Wave packet dynamics initiated by a vertical π → π∗ excitation is studied and particular emphasis is put on the investigation of the evolution of diabatic and adiabatic state populations. A new algorithm for computing the adiabatic state populations from diabatically represented wavefunctions is discussed and applied here for the first time. We have used the potential model of ethene which was derived by Krawczyk et al. [R.P. Krawczyk, A. Viel, U. Manthe, W. Domcke, Photoinduced dynamics of the valence states of ethene: a six-dimensional potential-energy surface of three electronic states with several conical intersections. J. Chem. Phys.119 (2003) 1397-1411] and the kinetic energy operator derived by Viel et al. [A. Viel, R.P. Krawczyk, U. Manthe, W. Domcke, Photoinduced dynamics of ethene in the N, V and Z valence states: a six-dimensional nonadiabatic quantum dynamics investigation, J. Chem. Phys.120 (2004) 11000-11010]. However, a second kinetic energy operator, which is more accurate than the first one, was derived and applied. The results of our calculations are in qualitative agreement with the previous ones of Viel et al., but there are marked quantitative differences.