Theoretical Methods for Excited States and Photochemistry in Complex Environments

The research of the Neugebauer group focuses on the development of quantum mechanical methods for electronically excited states of complex chemical systems, which are out of reach for conventional electronic structure methods. These include i.a. chromophores in protein complexes, as inclusion compounds, in solution or immobilized on surfaces. These methods are applied to investigate the properties of light-responsive organic materials on increasingly realistic models.

The group develops its own, open-source quantum chemistry program SERENITY, which provides a large variety of subsystem- and embedding methods suited for complex systems. Through the development of exact quantum chemical embedding methods for excited states, we have provided an important benchmark possibility for more efficient, yet more approximate embedding methods. Such methods also enable accurate calculations of energy- and electron-transfer parameters.

Illustration reference: 4.

Relevant preliminary work:

1. Inter-subsystem charge-transfer excitations in exact subsystem time-dependent density-functional theory
   Tölle J, Böckers M, Neugebauer J. J.Chem. Phys. 151, 174109 (2019)
2. Exact subsystem time-dependent densityfunctional theory
   Tölle J, Böckers M, Neugebauer J. J.Chem. Phys. 150, 181101 (2019)
3. SERENITY: A Subsystem Quantum Chemistry Program
   Unsleber J P,† Dresselhaus T,† Klahr K, Schnieders D, Böckers M, Barton D,§ Neugebauer J.* J. Comp. Chem. 39, 788-798 (2018)
4. Including Protein Density Relaxation Effects in First-Principles Embedding Calculations of Cofactor Excitation Energies
   Goez A, Neugebauer J. Mol. Phys. (2016)
5. Analytical Gradients for Excitation Energies from Frozen-Density Embedding
   Kovyrshin A, Neugebauer J. Phys. Chem. Chem. Phys. 18, 20955-20975 (2016)
6. State-Specific Embedding Potentials for Excitation-Energy Calculations
   Daday C, König C, Valsson O, Neugebauer J, Filippi C. J. Chem. Theory Comput. 9, 2355-2367 (2013)