Theoretical Physical Chemistry and Molecular Physics
interfaced with experiments:

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Strategies to understand, elucidate and tailor the properties of biomolecules and soft matter 


Research direction I:"Biomolecular simulation techniques interfacing theory and experiment"


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Te aim of this research is to interconnect experimental techniques (that often proivide insufficient spacial resolution for establishing atomistic structural models) with atomistic simulations by biasing techniques. This hybrid experimental-theoretical approach is particularly useful for systems with structural heterogeneities that are hard to characterize by high-resolution methods (because of dynamic mixtures or in case of disordered systems). The main advantage of experiments-guided methods is to narrow down the configurational space that has to be explored theoretically so that less time is spent on sampling configurations that are incompatible with experimental observations. The main challenge is to nevertheless fully explore and sample all present heterogeneities which makes a combination of restraints with sysematic acceleration of the exploration necessary.

  • Guided and adaptively biased Molecular Dynamics driven by gasphase spectrometric and spectroscopic input.

    DFG project Ku 3251/1-1 (Link to the DFG project page)

  • Bioinformatics approaches for interoperability between classical and quantum-chemical simulations

    High performance computing project  LI03p at the CINECA with C. Greco University Milan-Bicocca, Italy

    SinPI: "Systematic ab-initio Investigation of Protein-imposed Influence in [NiFe]-hydrogenase fragments"

Results: Replica Exchange MD for Chromophor functionalized Amyloid-β peptides


Research direction II:"Understanding Photophysics and Modelling of Excited States and Energy Transfer "


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In this part of my research, I am concerned with describing the photophysics using theoretical and computational approaches in close collaboration with experimental spectroscopies. Electronic excitation provides access to structure-specific response by different probes (tuning through the energetic spectrum) while being straightforwardly predictable by ab-initio theories. However, special care has to be taken in chosing the right electronic structure method for the right reason. Charge transfer contamination by spurious intruder states,  doubly excited configurations, dynamic and static correlation effects or diffuse states of Rydberg character are the main obstacles to be overcome in this regard. Additionallly, the processes upon photoexcitation are not limited to vertical transitions from their ground state geometries in reality. Therefore strategies to describe nuclear-electronic coupling, dynamics in ground- and excited states, multiphoton absorption and the relaxation to the ground state via deactivation pathways such as fluorescence or fragmentation have to be considered.


Research direction III:"Nanomaterials and their hybrid systems with soft matter"


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Whenever materials with inherently different properties are combined to a hybrid material, novel properties may emerge that are not present in either component alone. These emergent properties are the focus of this research direction where special attention is given to conjugates of metal atoms, ions clusters and particles with soft matter such as biomolecules (proteins, DNA), organic ligands or polymers. The research aims at proposing new material combinations and understanding of their interfacial regions at the molecular scale. In this way, new technologies with application from for medical diagnostics to energy storage and conversion might be in reach in the near future. Examples encompass:


  • Optical and structural properties of metal cluster biomolecule hybrid systems

  • The effect of a stabilizing environments on optical properties of cluster biomolecule hybrid systems

  • The influence of the nature of environment on electronic structure and geometry of subnanoclusters


Results:  Metal Clusters for Biosensor Applications




  • Molecular dynamics and Monte Carlo methods

  • Global optimization using  a) simulated annealing, basin hopping, evolutionary algorithms

  • Generalized Ensemble methods for MD-sampling (Replica-exchange MD & Parallel Tempering)

  • Free-energy methods (Free Energy perturbation, Stratified Umbrella-like Sampling, Metadynamics, etc.)

  • Tailored (e.g. FRET) experiments-guided sampling methods (effective, apadtive biases, tailored order parameters)

Ground State Properties:

  • Density functional theory (GTO-based and PW-PP/PAW approach for isolated and periodic systems).

  • Correlated ab-initio methods such as CCSD(T)

  • Reaction path elucidation (e.g. String-algorithm) and transition state search

Excited States:

  • Excited State properties via LR-TDDFT or EOM/LR-CC methods, multireference methods

  • Multiphoton process models and excitation energy transfer models.

  • Vibronic coupling