Research

1) Hybrid Quantum Mechanical/Molecular Mechanical Molecular Dynamics

The hybrid QM/MM approach of the department initially used solely for investigations of single ion hydration has been successfully extended to the treatment of coordination complexes, aqueous proton transfer, biomolecular systems and solid-state interfaces.

Typical examples of treated systems are:

Hydrogen-evolving complexes
Lewis-acid induced proton transfer
Drug-ligand interactions
Characterisation of solid/aqueous interfaces

The development and implementation of improved QM/MM formulations represents an important focus of the research activities of the group in addition to the broad application of the methodology.

2) Vibrational Spectroscopy via grid-based approaches

Grid-based solutions have been widely used to study quantum phenomena such as the vibrational motion of molecular systems. Especially in case of the increasingly important field of near-infrared (NIR) spectroscopy grid-based appraoches provide a substantial increase in accuracy over standard methods such as the harmonic approximation. The extension to higher dimensions (2D, 3D) also provides access to explicitly investigate the influence of mode-mode coupling on quantum mechanical level. In addition to the application method development is another important aspect of this project as for example:

Formulation of accurate numerical integration via higher order stencils
Reduction of grid-points via interpolation strategies
Exploitation of sparse matrix algebra
Characterisation of mode coupling potentials

Special focus is given on the influence of different modes of binding (hydrogen vs covalent bonds, halogen bonding, etc.) and their influence on the coupling characteristics between individual vibrational modes.