T. A. Niehaus

Atomistic simulations of self-trapped exciton formation in silicon nanostructures: The transition from quantum dots to nanowires (2009)

Wang, Y., Zhang, R. Q., Frauenheim, Th., Niehaus, T. A.

Using an approximate time-dependent density functional theory method, we calculate the absorption and luminescence spectra for hydrogen passivated silicon nanoscale structures with large aspect...

Efficient evaluation of the Fourier Transform over products of Slater-type orbitals on different centers (2008)

Niehaus, T. A., López, R., Rico, J. F.

Using the shift-operator technique, a compact formula for the Fourier transform of a product of two Slater-type orbitals located on different atomic centers is derived. The result is valid for...

Resonant electron heating and molecular phonon cooling in single C$_{60}$ junctions (2008)

Schulze, G., Franke, K. J., Gagliardi, A., Romano, G., Lin, C. S., Da Rosa, A., ...

We study heating and heat dissipation of a single \c60 molecule in the junction of a scanning tunneling microscope (STM) by measuring the electron current required to thermally decompose the...

Dynamical generalization of a solvable family of two-electron model atoms with general interparticle repulsion (2007)

Niehaus, T. A., Suhai, S., March, N. H.

Holas, Howard and March [Phys. Lett. A {\bf 310}, 451 (2003)] have obtained analytic solutions for ground-state properties of a whole family of two-electron spin-compensated harmonically confined...

Use of Vibrational Spectroscopy to Study Protein and DNA Structure, Hydration, and Binding of Biomolecules: A Combined Theoretical and Experimental Approach (2006)

Jalkenen, K. J., Juergensen, V. Wuertz, Claussen, A., Rahim, A., Jensen, G.M., Wade, R.C., ...

No abstract.

Use of Vibrational Spectroscopy to Study Protein and DNA Structure, Hydration, and Binding of Biomolecules: A Combined Theoretical and Experimental Approach (2006)

Jalkenen, K. J., Juergensen, V. Wuertz, Claussen, A., Rahim, A., Jensen, G.M., Wade, R.C., ...

No abstract.

Influence of copper on the electronic properties of amorphous chalcogenides (2005)

Simdyankin, S. I., Elstner, M., Niehaus, T. A., Frauenheim, Th., Elliott, S. R.

We have studied the influence of alloying copper with amorphous arsenic sulfide on the electronic properties of this material. In our computer-generated models, copper is found in two-fold...

Importance of electronic self-consistency in the TDDFT based treatment of nonadiabatic molecular dynamics (2004)

Niehaus, T. A., Heringer, D., Torralva, B., Frauenheim, Th.

A mixed quantum-classical approach to simulate the coupled dynamics of electrons and nuclei in nanoscale molecular systems is presented. The method relies on a second order expansion of the...

Quasiparticle energies for large molecules: a tight-binding GW approach (2004)

Niehaus, T. A., Rohlfing, M., Della Sala, F., Di Carlo, A., Frauenheim, Th.

We present a tight-binding based GW approach for the calculation of quasiparticle energy levels in confined systems such as molecules. Key quantities in the GW formalism like the microscopic...

A new type of charged defect in amorphous chalcogenides (2004)

Simdyankin, S. I., Niehaus, T. A., Natarajan, G., Frauenheim, Th., Elliott, S. R.

We report on density-functional-based tight-binding (DFTB) simulations of a series of amorphous arsenic sulfide models. In addition to the charged coordination defects previously proposed to exist in...

Simulation of the physical properties of the chalcogenide glass As$_2$S$_3$ using a density-functional-based tight-binding method (2003)

Simdyankin, S. I., Elliott, S. R., Hajnal, Z., Niehaus, T. A., Frauenheim, Th.

We have used a density-functional-based tight-binding method in order to create structural models of the canonical chalcogenide glass, amorphous (a-)As$_2$S$_3$. The models range from one containing...