We employ high-level wavefunction based methods within the framework of an embedded cluster approach (ECA) to study strongly localized defects and excitations in solids and at surfaces, as well as the ensuing dynamical processes on fast timescales. The ECA allows the application of state-of-the-art quantum mechanical techniques beyond mean-field descriptions to scenarios where correlation effects and/or excited states are crucial, yet a full wavefunction treatment of the extended system is still out of reach.
The goal of this project is to combine high-level correlated wavefunction (CW) methods such as the multi-reference configuration interaction or the complete active space self-consistent field methods applicable only to small systems with lower level methods such as tight-binding and density functional theory for the extended system. Key is the development of embedding potentials that self-consistently couple the active cluster with the environment. Primary goal during the second period is to extend this approach to explicitly time dependent (TD) systems and to construct the TD embedding potential that interfaces the TD-CW description of the active cluster with TD-DFT for the environment. Collaborations will include implementation of embedding into VASP (P02), simulation of exciton dynamics in photovoltaic materials (P03), application of embedding for the calculation of ground state and time evolution of quasi-one-dimensional systems (P04), exploration of alternative TD-CW methods (P06), benchmarking the ECA description of localized excitation against post-DFT methods (P07), and providing input data for P13 and P16.
| Burgdörfer, Joachim Principal Investigator, P05 | Vienna University of Technology Institute of Theoretical Physics |
| Libisch, Florian National Research Partner, P05 | Vienna University of Technology Institute of Theoretical Physics |
| Lemell, Christoph Participating Researcher, P05 | Vienna University of Technology Institute of Theoretical Physics |
 | Chizhova, Larisa Participating Researcher, P05 | Vienna University of Technology Institute of Theoretical Physics |
 | Wachter, Georg | Vienna University of Technology Institute of Theoretical Physics |
