Towards quantitative accuracy in first-principles transport calculations: The GW method applied to alkane/gold junctions

• Mikkel Strange and
• Kristian S. Thygesen

Beilstein J. Nanotechnol. 2011, 2, 746–754, doi:10.3762/bjnano.2.82

• length dependence: Gn = Gc exp(−βn). The main difference from standard density functional theory (DFT) calculations is a significant reduction of the contact conductance, Gc, due to an improved alignment of the molecular energy levels with the metal Fermi energy. The molecular orbitals involved in the

• results cannot be mimicked by DFT calculations employing a simple scissors operator. Keywords: alkanes; density functional theory; electron transport; gold junction; GW; Introduction The conductance of a molecule sandwiched between metallic electrodes is sensitive to the chemical and electronic

• calculations for Cn-alkanediamine molecules with n = 2,4,6 we show that the erroneous Gc values are a result of the incorrect level alignment in the DFT calculations. Indeed, GW yields a Gc in close agreement with the experimental values. We find a pronounced orbital and length dependence of the quasiparticle

Distinction of nucleobases – a tip-enhanced Raman approach

• Regina Treffer,
• Xiumei Lin,
• Elena Bailo,
• Tanja Deckert-Gaudig and
• Volker Deckert

Beilstein J. Nanotechnol. 2011, 2, 628–637, doi:10.3762/bjnano.2.66

• atoms: The pyrimidine N1 and N3, the imidazole N7 and the N10 of the exocyclic NH2 group. N9 is the binding site to the ribose and therefore cannot bind to the metal nanoparticle. Density functional theory (DFT) calculations show changes in Raman band intensities and positions for the four respective

Towards a scalable and accurate quantum approach for describing vibrations of molecule–metal interfaces

• David M. Benoit,
• Bruno Madebene,
• Inga Ulusoy,
• Luis Mancera,
• Yohann Scribano and
• Sergey Chulkov

Beilstein J. Nanotechnol. 2011, 2, 427–447, doi:10.3762/bjnano.2.48

Septipyridines as conformationally controlled substitutes for inaccessible bis(terpyridine)-derived oligopyridines in two-dimensional self-assembly

• Daniel Caterbow,
• Daniela Künzel,
• Michael G. Mavros,
• Axel Groß,
• Katharina Landfester and
• Ulrich Ziener

Beilstein J. Nanotechnol. 2011, 2, 405–415, doi:10.3762/bjnano.2.46

• HOPG/solution interface if the orientation of the peripheral nitrogen atoms in the BTPs and the PhSpPys stays the same, was supported by comparing the STM images of the pairs 2,2'-BTP (5)/2,2'-PhSpPy (14) and 3,3'-BTP (3)/3,3'-PhSpPy (15). DFT calculations carried out for additional support showed that

Simulation of bonding effects in HRTEM images of light element materials

• Simon Kurasch,
• Jannik C. Meyer,
• Daniela Künzel,
• Axel Groß and
• Ute Kaiser

Beilstein J. Nanotechnol. 2011, 2, 394–404, doi:10.3762/bjnano.2.45

• an accurate 3D potential is obtained and renormalized it can be used for TEM image simulation. Thereby each direction of the incident beam can be modeled by rotating the 3D potential using linear interpolation algorithms. Influence of DFT parameters In order to set up meaningful DFT calculations, it

Influence of water on the properties of an Au/Mpy/Pd metal/molecule/metal junction

• Jan Kučera and
• Axel Groß

Beilstein J. Nanotechnol. 2011, 2, 384–393, doi:10.3762/bjnano.2.44

• units in possible nanoelectronic devices. We have investigated the interaction between water and a palladium monolayer of a Au(111)/4-mercaptopyridine/Pd junction by means of DFT calculations. A relatively strong bond between water and the palladium monolayer of the Au/Mpy/Pd complex is observed via a

• molecules, periodic density functional theory (DFT) calculations of the bare Au/ATP/Pd junction, assuming a () structure of the ATP molecules, were able to reproduce the experimentally observed downshift of the Pd DOS reasonably well [2][12] under the assumption that the amino groups of the ATP molecules

• become dehydrogenated upon the metalization. The isolated nitrogen atom of the dehydrogenated amino group interacts strongly with three Pd atoms thus causing the strong modification of the DOS. In the case of the Au/Mpy/Pd junction, on the other hand, the DFT calculations for the bare system only yield a

Intermolecular vs molecule–substrate interactions: A combined STM and theoretical study of supramolecular phases on graphene/Ru(0001)

• Michael Roos,
• Benedikt Uhl,
• Daniela Künzel,
• Harry E. Hoster,
• Axel Groß and
• R. Jürgen Behm

Beilstein J. Nanotechnol. 2011, 2, 365–373, doi:10.3762/bjnano.2.42

• different behavior of the PTCDA molecules, we again compare the corrugation of the adsorption energy with the intermolecular interaction between adjacent molecules in the herringbone configuration of PTCDA. Recent DFT calculations by Mura et al. [26] have shown that the stabilization energy per molecule is

• for the inclusion of van der Waals interactions in standard DFT calculations. These two contributions (adsorbate–graphene and adsorbate–metal) were then added in order to obtain total adsorption energies of the molecules on the graphene/Ru(0001) substrate. (a) Defect free graphene/Ru(0001) surface

Defects in oxide surfaces studied by atomic force and scanning tunneling microscopy

• Thomas König,
• Georg H. Simon,
• Lars Heinke,
• Leonid Lichtenstein and
• Markus Heyde

Beilstein J. Nanotechnol. 2011, 2, 1–14, doi:10.3762/bjnano.2.1

• level of the MgO/Ag(001) system [32], the charge density is also responsible for the strong peak in the tunneling current signal. Further insights into the interaction of tip and color center are obtained by periodic supercell DFT calculations at the level of the generalized gradient approximation as

• , divacancies formed at step and corner sites since the formation energy at these sites is the lowest. The stability of divacancies and their electron affinity have been confirmed by DFT calculations [39]. A divacancy is neutral compared with the surrounding MgO, since a complete Mg-O unit is missing. Due to the

• . For the sake of simplicity, we focus on straight APDBs in this section. A more comprehensive NC-AFM study of the ADPBs and other line defects on aluminum oxide in NiAl(110) can be found in [43][45][46]. By DFT calculations [47], the stoichiometry of the film with a straight APDB was determined to be

On the reticular construction concept of covalent organic frameworks

• Binit Lukose,
• Agnieszka Kuc,
• Johannes Frenzel and
• Thomas Heine

Beilstein J. Nanotechnol. 2010, 1, 60–70, doi:10.3762/bjnano.1.8

• -DFT calculations, they are typically in the correct range within the DFTB method. For validation of our method, we have calculated some of the structures using Density Functional Theory (DFT) as implemented in ADF code [25][26]. Periodic boundary conditions were used to represent frameworks of the

• were computed along lines between high symmetry points of the Brillouin zone with 50 k-points each along each line. XRD patterns have been simulated using Mercury software [28][29]. We have also performed first-principles DFT calculations at the PBE [30] /DZP [31] level to support our results