Theoretical developments and methodology
E. Fromager, E. Gindensperger, R. Marquardt
|
The theoretical methods which are developed in our lab have various purposes. One of them is the description of electron correlation, in both ground and excited states, in molecular systems that contain heavy elements. We currently derive, implement and test methods that aim at combining the best of wave function and density-functional theories, with respect to computational cost and accuracy, at both non-relativistic and relativistic levels. The computational implementation of those models is performed in the DALTON and DIRAC program packages. |
|
|
Potential functions of (CH3)3SnI |
Another part of the methodological developments currently carried out in this laboratory is devoted to the study of molecular quantum dynamics, and includes three sub-streams: the development of simple, yet accurate analytical formulae for the representation of global potential energy surfaces of polyatomic molecules; the solution of the time-independent Schrödinger equation to obtain ro-vibrational eigenstates; the solution of the time-dependent Schrödinger equation in the space of nuclear and electronic motion to disclose wave packet evolutions therein, for instance within the URIMIR program package (“Unimolecular Reactions Induced by Monochromatic Infrared Radiation”). The figure shows representations of potential energy surfaces of the (CH3)3SnI compound (1D sections as a function of the SnI bond length). All lines are obtained with the same, simple, 6 parameter analytical function related to a modified Morse potential. |
