Two Preprints: Wavefunction analysis

Two new preprints dealing with the analysis of excited-state electronic wavefunctions are available from ChemRxiv.

First, a quick summary of the TheoDORE package: TheoDORE: a Toolbox for a Detailed and Automated Analysis of Electronic Excited State Computations.

Second, a more extensive paper exploring how far we can use information from excited-state wavefunction analysis tools to understand excitation energies beyond the molecular orbital picture. The energy of a correlated electron-hole pair is derived using diagrammatic techniques and this information is further used for a graphical depiction in terms of different charge distributions and their electrostatic potentials. Doing so turned out not as easy as hoped for but was very exciting. Find more here: Toward an Understanding of Electronic Excitation Energies Beyond the Molecular Orbital Picture by P. Kimber and F. Plasser.

Preprint: Details in the surface hopping algorithm

Having discussed the influence of electronic structure methods in surface hopping dynamics in the last post and paper, we can now proceed to the surface hopping algorithm itself. To our surprise, algorithmic details such as the decoherence correction (energy-based decoherence or augmented FSSH), momentum rescaling and the treatment of frustrated hops can make a big difference. This is what we investigated in our new preprint “Strong Influence of Decoherence Corrections and Momentum Rescaling in Surface Hopping Dynamics of Transition Metal Complexes” available on ChemArxiv.

To have a well-defined reference, we used our new implementation of vibronic coupling models for surface hopping, which allows us to have a one-to-one comparison with accurate quantum dynamics computed at the MCTDH level of theory. As model system, we used a rhenium complex and studied its ultrafast intersystem crossing dynamics from the singlet to the triplet manifold following previous studies by our collaborators in Strasbourg [JCTC (2017), PCCP (2018)].