Density functional theory (DFT) calculations were performed to investigate the properties of planar, tubular and conical forms of silicon nanostructures. The evaluated parameters including averaged bond lengths, binding energies, gap energies and dipole moments were then evaluated for the optimized models of study. The results indicated that the bond lengths between silicon atoms are different ...

Density functional theory (DFT) calculations were performed to investigate the properties of planar, tubular and conical forms of silicon nanostructures. The evaluated parameters including averaged bond lengths, binding energies, gap energies and dipole moments were then evaluated for the optimized models of study. The results indicated that the bond lengths between silicon atoms are different ...

in this work, we have studied binding of clonidine drug (c9h9cl2n3) with zigzag single walled carbonnanotubes (swcnt) (5, 0) by theoretical methods of theory using gaussian 09 software package.binding energies, nmr parameters and homo- lumo gap energy were calculated. results frombinding energies indicate that it is possible thermodynamically to bind clonidine drug to swcnt.the calculated nmr p...

A simple approach is presented for using bond-stretching and bond-bending modes to describe the static deformations of carbon nanotubes and related actuation effects. This approach allows us to analyze various phenomena in a unified way and to clarify their relationships. We discuss gap energy modulation by external strains, dimensional and torsional deformations caused by charge injection, and...

A net-like nanostructure of silicon named silicon nanonet was designed and oxygen atoms were used to passivate the dangling bonds. First-principles calculation based on density functional theory with the generalized gradient approximation (GGA) were carried out to investigate the energy band gap structure of this special structure. The calculation results show that the indirect-direct band gap ...

the one-dimensional model of lippincott and schroeder for hydrogen bond has been re-examined and it has been shown that o-h bond distance depends on repulsive van der waals and attractive electrostatic potentials.it has been shown that constant b in the van der waals repulsion potential is not transferable to all hydrogen bonds. the possibility of obtaining the semi-empircal parameters in the l...

Density functional theory (UB3LYP/6-31G(d,p)) was used to determine substituent effects on the singlet-triplet-state energy gap for 21 meta-substituted phenylnitrenium ions. It was found that strongly electron-donating substituents stabilize the triplet state relative to the singlet state. With sufficiently strong meta electron donors (e.g., m,m'-diaminophenylnitrenium ion) the triplet is predi...

This paper presents results of the spectral (absorption and emission) and photophysical study of 6-aminocoumarin (6AC) in various aprotic hydrogen-bond forming solvents. It was established that solvent polarity as well as hydrogen-bonding ability influence solute properties. The hydrogen-bonding interactions between S1-electronic excited solute and solvent molecules were found to facilitate the...

The interactions of oxygen atoms on the GaAs 001 2 2 4 surface and the passivation of oxidized GaAs 001 2 2 4 surface were studied by density functional theory. The results indicate that oxygen atoms adsorbed at back-bond sites satisfy the bond saturation conditions and do not induce surface gap states. However, due to the oxygen replacement of an As dimer atom at a trough site or row site, the...