Thomas S. Hofer

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A systematic investigation of three different electron-electron entanglement measures, namely the von Neumann, the linear and the occupation number entropy at full configuration interaction level has been performed for the four helium-like systems hydride, helium, Li(+) and Be(2+) using a large number of different basis sets. The convergence behavior of the(More)
A simulation of phosphate in aqueous solution was carried out employing the new QMCF MD approach which offers the possibility to investigate composite systems with the accuracy of a QMMM method but without the time consuming creation of solute-solvent potential functions. The data of the simulations give a clear picture of the hydration shells of the(More)
Classical molecular dynamics (MD) and combined quantum mechanical/molecular mechanical (QM/MM) MD simulations have been performed to investigate the structural and dynamical properties of the Tl(III) ion in water. A six-coordinate hydration structure with a maximum probability of the Tl-O distance at 2.21 A was observed, which is in good agreement with(More)
Quantum mechanical/molecular mechanical (QM/MM) and quantum mechanical charge field (QMCF) molecular (MD) simulations have been performed to describe structural and dynamical properties of Na(I) and K(I) in water and to compare the two approaches. The first and second hydration shells were treated by ab initio quantum mechanics at the restricted(More)
Based on a systematic investigation of trajectories of ab initio quantum mechanical/molecular mechanical simulations of numerous cations in water a standardized procedure for the evaluation of mean ligand residence times is proposed. For the characterization of reactivity and structure-breaking/structure-forming properties of the ions a measure is derived(More)
Structural properties of the hydrated Rb(I) ion have been investigated by ab initio quantum mechanical/molecular mechanical (QM/MM) molecular dynamics (MD) simulations at the double-zeta HF quantum mechanical level. The first shell coordination number was found to be 7.1, and several other structural parameters such as angular distribution functions, radial(More)
An implementation strategy for a dissociative water potential in hybrid QM/MM simulations is outlined. As the knowledge of the time-dependent topology is crucial for the assignment of solvent molecules to the QM or MM subregion, proton transfer events and the associated change of the molecular composition have to be monitored as the simulation is(More)
Sets of finite-time Lyapunov exponents characterize the stability and instability of classically chaotic dynamical trajectories. Here we show that their sample distributions can contain subpopulations identifying different types of dynamics. In small isolated molecules these dynamics correspond to distinct elementary motions, such as isomerizations.(More)
Description: Advances in Quantum Chemistry presents surveys of current developments in this rapidly developing field. With invited reviews written by leading international researchers, each presenting new results, it provides a single vehicle for following progress in this interdisciplinary area. Publishes articles, invited reviews and proceedings of major(More)
The hydration of the Bi(III) ion was determined via an ab initio quantum mechanical charge field molecular dynamics (QMCF-MD) simulation. Ten picosecond sampling was carried out to determine structural and dynamical properties of the Bi(III) ion in aqueous solution. In the first hydration shell, the ion is 9-fold coordinated with a maximum probability of(More)