### Mathematisch-Naturwissenschaftliche Fakultät

## Institut für Physik

### Fachgebiet: Theoretische Physik

Betreuer: Prof. Dr. Ronald Redmer

**André** **Kietzmann**

(e-mail: andre.kietzmann@uni-rostock.de )

*Quantum Molecular Dynamics Simulations for Dense Fluids*

The method of Quantum molecular dynamics (QMD) simulations was used
to describe warm, dense fluids. First, thermal expanded, fluid alkali
metalls were investigated. The structural and electronic changes could
be explained in a wide temperature and density region, in good
agreement with experimental results. The second topic studied in this
thesis was the calculation of compressed He-fluids, where the thermal
equation of state was determined and used for the calculation of the
Hugoniot curve. For the first time it was possible to compute the
electrical conductivity of compressed He in an ab initio-approach. The
experimentally found nonmetal-to-metal-transition could be verified
with QMD-results. Furthermore, the fundamental physical processes were
described by analyzing the ion-ion pair correlation function and the
electronic density of states. The third topic was the investigation of
fluid Li in a wide temperature-density area. The electrical
conductivity could be calculated, and it was possible to distinguish
between two different experimental conductivity results, which are
partly in contradiction. The ion-ion pair correlation function, the
electronic density of states, and the charge density were investigated,
so that predictions of Neaton and Ashcroft for a dimerized ground state
in compressed Li could be proofed for the liquid state.