The recent nonempirical semilocal exchange functional of Armiento and Kümmel [Phys. Rev. Lett. 111, 036402 (2013)], AK13, incorporates a number of features reproduced by higher-order theory. The AK13 potential behaves analogously with the discontinuous jump associated with the derivative discontinuity at integer particle numbers. Recent works have established that AK13 gives a qualitatively imp...

We have performed density functional theory (DFT) calculations to investigate the properties of defect in arepresentative armchair model of silicon nanotubes (SiNTs). To this aim, the structures of pristine and defective(5,5) SiNTs have been optimized and the properties such as bond lengths, total energies, binding energies,.formation energies, gap energies, and dipole moments have been evaluat...

A combination of the best available theoretical techniques for energetics, dynamics, and thermodynamics is employed in an extensive study of Si(n) ( n = 20,25) clusters. For T = 0 we solve the electronic structure by the density functional and the highly accurate quantum Monte Carlo approaches. Finite temperature and dynamical effects are investigated by the ab initio molecular dynamics method....

the effective parameters of (5, 0) and (5, 5) single-wall carbon nanotubes during the interaction with carbon dioxide as sensors are determined. the interaction of carbon dioxide  molecules with internal and external walls of the nanotubes is studied using gaussian 03 coding by density functional theory (dft) at the b3lyp/6-311g level of theory. co2 rotation around tube axles vertically and par...

objective(s): adsorption of immucillin-a (bcx4430) molecule on the pristine and n-doped tio2 anatase nanoparticles were studied using the density functional theory (dft) calculations. the adsorption energy analysis indicated that tio2+immucillin-a complexes including oc-substituted tio2 have higher adsorption energy than the complexes with ot substituted tio2, thus providing more stable configu...

we have performed density functional theory investigations on the adsorption properties of ammonia molecule on the undoped and n-doped tio2 anatase nanoparticles. we have geometrically optimized the constructed undoped and n-doped nanoparticles in order to fully understand the adsorption behaviors of ammonia molecule. for tio2 anatase nanoparticles, the binding site is preferentially located on...

In this study, a full-potential density functional theory was used to investigate the effects of Ti substitution by different cations. In both rutile and anatase, Ti atom was replaced by Ce, Au, Sn, Ag, Mo, Nb, Zr, and Y. Phase stability, electronic structure and formation energy of oxygen vacancy were compared for rutile and anatase. The results indicated that substitution of Ce and Zr increas...

The electronic and structural properties of oligo- and polythiophenes that can be used as building blocks for molecular electronic devices have been studied by using periodic density functional theory calculations. We have in particular focused on the effect of substituents on the electronic structure of thiophenes. Whereas singly bonded substituents, such as methyl, amino or nitro groups, chan...