ab-initio – TechConnect Briefs

MedeA: An environment for ICME starting with atoms, and what we can learn from it

Saxe P., Materials Design, Inc., US

ICME is a grand vision, but there is an enormous amount of work needed to bring together experiment and simulation across the entire spectrum of length- and time-scales to go from atoms to cars, airplanes, [...]

Moisture Assisted Electron Transport in Si-C Nanotubes: an ab-initio study

Choudhary S., Qureshi S., IIT Kanpur, IN

We investigate the effect of moisture-chemisorption on the electron transport properties in a (8, 0) semiconducting silicon-carbide nanotube (SiCNT) by applying self consistent non-equilibrium Green’s function formalism in combination with the density-functional theory. The results [...]

Linear scaling techniques for first-principle calculations of large nanowire devices

Zhang D., Polizzi E., University of Massachusetts, FR

This paper aims to provide a sound basis to face the challenges in large scale atomistic simulations for applications ranging from material sciences and chemistry to nanoelectronics and bio-nanotechnology. In nanoelectronics, large scale ’ab-initio’ simulations [...]

A Quasimolecular Approach to the Field-effect Molecular Transistor: Theory and Application

Zhao Y.-L., Allison T., Mujica V., Gonzalez C., Marquez M., NIST Center for Theoretical and Computational Nanosciences, US

DFT-based modified quasimolecular approach has been developed and implemented for studying molecular conductance successfully, in the case of molecular bridges attached to metal electrodes (Gonzalez et al. J. Phys. Chem. B. 2004, 108, 18414). In [...]

Mechanics of silicon nanowires: size-dependent elasticity from first principles

Rudd R.E., Lee B., Lawrence Livermore National Laboratory, US

We have conducted a detailed study of the size dependence of the mechanical properties of silicon nanowires using first principles quantum mechanical calculation together with continuum mechanics theory and atomistic simulation based on empirical potentials. [...]

Fast Density-Functional-Theory Calculation With Q-Chem Program

Kong J., Brown S.T., Fusti-Monlar L., Shao Y., Q-Chem Inc., US

DFT (Density functional Theory) is an essential tool in the molecular modeling, especially for studies in biology and nanotechnology. A new algorithm is presented to improve the efficiency of the computation of exchange-correlation contributions, a [...]

First-principle Study for Neutral Indium Migration in Silicon

Yoon K-S, Won T., Inha University, KR

We could figure out the atomistic configurations and migration energy during indium diffusion in silicon through our ab-initio calculations, which consists of searching for saddle points from a minimum and reaction pathway between the two [...]

Electronic Structure and Transport in Biological Inorganic Hybrid Materials

Pandey R.R., Bruque N., Lake R.K., University of California Riverside, US

Chemical and biological hybrid organic-inorganic nanotechnology holds the promise to provide new capabilities for manufacturing functional nanosystems for a wide range of applications in engineering and biotechnology. We report fundamental studies used to model bio/inorganic [...]

Ab Initio Simulation on Mechanical and Electronic Properties of Nanostructures under Deformation

Umeno Y., Kitamura T., Kyoto University, JP

Nanostructures have been attracting attention because of their prominent properties, and their applications for novel devices with advanced functions have been attemted. Large stress and strain occur in local regions in materials with nanostructures owing [...]

Ab Initio Calculations on Magnetic Properties of Diluted Magnetic Semiconductors

Kim H., Kim Y-S, Kim H., Kim Y-S, Chung Y-C, Hanyang University, KR

Some diluted magnetic semiconductors (DMS), in which magnetic elements are substituted for a small fraction (~5%) of host elements in a semiconductor lattice, show ferromagnetism, and thus possess potential applicability in spintronics. To obtain quantum-mechanical [...]