DFT – Page 4 – TechConnect Briefs

Crystalline Magnetotunnel Junctions: Fe-MgO-Fe, Fe-FeOMgO-Fe and Fe-AuMgOAu-Fe

Stilling M., Stokbro K., Flensberg K., Copenhagen University, DK

The dimension of electronic devices is rapidly scaling down, and the ratio between surface and bulk atoms therefore increasing. This has the consequence that the interfaces between different parts of the device start to have [...]

Electronic Transport Through Carbon Nanotubes – Effect of Contacts, Topological Defects, Dopants and Chemisorbed Impurities

Maiti A., Hoekstra J., Andzelm J., Govind N., Ricca A., Svizhenko A., Mehrez H., Anantram M.P., Accelrys Inc., US

Electronics based on carbon nanotubes (CNT) has received a lot of attention recently because of its tremendous application potential, such as active components and interconnects in nanochips, nanoelectromechanical systems (NEMS), display devices, and chemical and [...]

Structure Determination of Small Metal Clusters by Density-Functional Theory and Comparison with Experimental Far-Infrared Spectra

Ratsch C., Fielicke A., Behler J., Scheffler M., von Helden G., Meijer G., University of California, Los Angeles, US

The far-infrared vibrational spectra for charged vanadium clusters as well as charged and neutral niobium clusters have been measured size specifically using farinfrared multiple photon dissociation. The ground state energy and vibrational spectra of a [...]

The Two-Layer ONIOM Technique in the Studies of Chemical Reactions on Carbon Nanotube Tips

Basiuk E.V., Basiuk V.A., Basiuk E.V., Basiuk V.A., Universidad Nacional Autonoma de Mexico, MX

In continuation of our combined quantum mechanics/molecular mechanics (QM/MM) studies of selective amidation (reaction 1) and esterification (reaction 2) of monocarboxy-substituted tips of zigzag and armchair single-walled carbon nanotube (SWNTs), we studied theoretically the interaction [...]

Proton Polarization on Pt Surface with Water Molecules

Yamamoto T., Ohnishi S., Watari N., NEC Fundamental Resreach Labs., JP

We present theoretical studies of atomic and electronic structures calculations of hydrogen at Pt surfaces with H2O molecules by focusing on the mechanism of proton polarization in the fuel cells system by the density functional [...]

DNA base damage: A Car-Parrinello Molecular Dynamics Study of Guanine and Thymine with an OH Radical

Wu Y., Mundy C.J., Colvin M.E., Car R., Lawrence Livermore National Labs, US

Understanding the basic chemistry of radicals and DNA bases is an important step in characterizing the potential damage to DNA. The chemical level understanding of such damage has far reaching implications for radiation therapy, health [...]

The Electronic Properties and L3 XANES of Au and Nano-Au

Yiu Y.M., Zhang P., Sham T.K., University of Western Ontario, CA

The electronic properties of Au crystal and nano Au have been investigated by theory and experiment. Molecularly capped nano-Au was synthesized using the two-phase method. Au nano-particles have been characterized by X-Ray Diffraction (XRD) and [...]

DNA base damage: A Car-Parrinello Molecular Dynamics Study of Guanine and Thymine with an OH Radical

Wu Y., Mundy C.J., Colvin M.E., Car R., Lawrence Livermore National Labs, US

Understanding the basic chemistry of radicals and DNA bases is an important step in characterizing the potential damage to DNA. The chemical level understanding of such damage has far reaching implications for radiation therapy, health [...]

X-ray Absorption Near Edge Structures at the L3,2 and M3,2 edges: A probe for the electronic behavior of metal nanostructures

Yiu Y.M., Sham T.K., The University of Western Ontario, CA

We present a comparison of the calculation and experiment results of the X-ray Absorption Near Edge Structures (XANES) of the L 3,2-edges and the M 3,2 -edges of representative 5d metals. Emphasis is placed on [...]