#### Filter Results:

- Full text PDF available (9)

#### Publication Year

2002

2009

- This year (0)
- Last 5 years (0)
- Last 10 years (6)

#### Publication Type

#### Co-author

#### Journals and Conferences

#### Key Phrases

Learn More

- Aaron Puzder, Andrew J. Williamson, Fernando Agustín Reboredo, Giulia Galli
- Physical review letters
- 2003

We present density functional and quantum Monte Carlo calculations of the stability and optical properties of semiconductor nanomaterials with reconstructed surfaces. We predict the relative stability of silicon nanostructures with reconstructed and unreconstructed surfaces, and we show that surface step geometries unique to highly curved surfaces… (More)

- Valentino R. Cooper, Timo Thonhauser, Aaron Puzder, Elsebeth Schröder, Bengt I. Lundqvist, David C. Langreth
- Journal of the American Chemical Society
- 2008

The importance of stacking interactions for the Twist and stability of DNA is investigated using the fully ab initio van der Waals density functional (vdW-DF). Our results highlight the role that binary interactions between adjacent sets of base pairs play in defining the sequence-dependent Twists observed in high-resolution experiments. Furthermore, they… (More)

T. Thonhauser,1 Valentino R. Cooper,1 Shen Li,1 Aaron Puzder,1 Per Hyldgaard,2 and David C. Langreth1 1Department of Physics and Astronomy, Rutgers, The State University of New Jersey, Piscataway, New Jersey 08854-8019, USA 2Department of Microtechnology and Nanoscience, Chalmers University of Technology, SE-412 96 Göteborg, Sweden Received 16 March 2007;… (More)

- David C. Langreth, Bengt I. Lundqvist, +13 authors Timo Thonhauser
- Journal of physics. Condensed matter : an…
- 2009

Sparse matter is abundant and has both strong local bonds and weak nonbonding forces, in particular nonlocal van der Waals (vdW) forces between atoms separated by empty space. It encompasses a broad spectrum of systems, like soft matter, adsorption systems and biostructures. Density-functional theory (DFT), long since proven successful for dense matter,… (More)

- Andrew J. Williamson, Jeffrey C. Grossman, Randolph Q. Hood, Aaron Puzder, Giulia Galli
- Physical review letters
- 2002

Quantum Monte Carlo (QMC) calculations of the optical gaps of silicon quantum dots ranging in size from 0 to 1.5 nm are presented. These QMC results are used to examine the accuracy of density functional (DFT) and empirical pseudopotential based calculations. The GW approximation combined with a solution of the Bethe-Salpeter equation performs well but is… (More)

- Aaron Puzder, Andrew J. Williamson, François Gygi, Giulia Galli
- Physical review letters
- 2004

Ab initio calculations of the structural, electronic, and optical properties of CdSe nanoparticles are presented. The atomic structures of the clusters are relaxed both in vacuum and in the presence of surfactant ligands. In both cases, we predict significant geometrical rearrangements of the nanoparticle surface while the wurtzite core is maintained. These… (More)

Density functional and quantum Monte Carlo calculations are employed to determine the effect of surface passivants on the optical gap of silicon nanoclusters. Our results show that quantum confinement is only one mechanism responsible for visible photoluminescence and that the specific surface chemistry must be taken into account in order to interpret… (More)

- Aaron Puzder, Andrew J. Williamson, Jeffrey C. Grossman, Giulia Galli
- Physical review letters
- 2002

We employ density functional and quantum Monte Carlo calculations to show that significant changes occur in the gap of fully hydrogenated nanoclusters when the surface contains passivants other than hydrogen, in particular atomic oxygen. In the case of oxygen, the gap reduction computed as a function of the nanocluster size provides a consistent… (More)

- Aaron Puzder, Andrew J. Williamson, Jeffrey C. Grossman, Giulia Galli
- Journal of the American Chemical Society
- 2003

We have computed absorption and emission energies of silicon nanocrystals as a function of size and of surface passivants, using both density functional theory and quantum Monte Carlo calculations. We have found that the ionic rearrangements and electronic relaxations occurring upon absorption and emission are extremely sensitive to surface chemistry. In… (More)

- Timo Thonhauser, Aaron Puzder, David C. Langreth
- The Journal of chemical physics
- 2006

We present density functional calculations for the interaction energy of monosubstituted benzene dimers. Our approach utilizes a recently developed fully nonlocal correlation energy functional, which has been applied to the pure benzene dimer and several other systems with promising results. The interaction energy as a function of monomer distance was… (More)