Ab Initio Modeling of MultiWall: A General Algorithm First Applied to Carbon Nanotubes.

A general, versatile and automated computational algorithm to design any type of multiwall nanotubes of any chiralities is presented for the first time. It can be applied to rolling up surfaces obtained from cubic, hexagonal, and orthorhombic lattices. Full exploitation of the helical symmetry permits a drastic reduction of the computational cost and therefore opens to the study of realistic systems.

Role of Surfaces in the Magnetic and Ozone Gas-Sensing Properties of ZnFeO Nanoparticles: Theoretical and Experimental Insights.

The magnetic properties and ozone (O) gas-sensing activity of zinc ferrite (ZnFeO) nanoparticles (NPs) were discussed by the combination of the results acquired by experimental procedures and density functional theory simulations. The ZnFeO NPs were synthesized via the microwave-assisted hydrothermal method by varying the reaction time in order to obtain ZnFeO NPs with different exposed surfaces and evaluate the influence on its properties. Regardless of the reaction time employed in the synthesis, the zero-field-cooled and field-cooled magnetization measurements showed superparamagnetic ZnFeO NPs with an average blocking temperature of 12 K.

Intra-octahedral distortion on lamellar potassium niobate KNbO: a periodic DFT study of structural, electronic and vibrational properties.

Structural, electronic and spectroscopic properties of the anhydrous KNbO niobate were investigated in the bulk phase using periodic density functional theory (DFT) calculations with global hybrid (B3LYP) and also including dispersion corrections (B3LYP-D3). The degree of native distortion of different niobium octahedra (here named [NbO], or [NbO]) were quantified in terms of the effective coordination number (ECoN) and of other classical descriptors of local deformation and were correlated with the electronic structure. The effect of intrinsic deformation was also examined using the quantum theory of atoms in molecules and crystals (QTAIMC), density of states and charge analyses.

A quantum-mechanical investigation of oxygen vacancies and copper doping in the orthorhombic CaSnO perovskite.

In this study we explore the implications of oxygen vacancy formation and of copper doping in the orthorhombic CaSnO3 perovskite, by means of density functional theory, focusing on energetic and electronic properties. In particular, the electronic charge distribution is analyzed by Mulliken, Hirshfeld-I, Bader and Wannier approaches. Calculations are performed at the PBE and the PBE0 level (for doping with Cu, only PBE0), with both spin-restricted and spin-unrestricted formulations; unrestricted calculations are used for spin-polarized cases and for the naturally open-shell cases (Cu doping).

Theoretical insight into the mechanism for the inhibition of the cysteine protease cathepsin B by 1,2,4-thiadiazole derivatives.

Several cellular disorders have been related to the overexpression of the cysteine protease cathepsin B (CatB), such as rheumatic arthritis, muscular dystrophy, osteoporosis, Alzheimer's disease, and tumor metastasis. Therefore, inhibiting CatB may be a way to control unregulated cellular functions and prevent tissue malformations. The inhibitory action of 1,2,4-thiadiazole (TDZ) derivatives has been associated in the literature with their ability to form disulfide bridges with the catalytic cysteine of CatB.

Joint experimental and theoretical analysis of order-disorder effects in cubic BaZrO3 assembled nanoparticles under decaoctahedral shape.

Periodic first-principles calculations based on density functional theory at the B3LYP level has been carried out to investigate the photoluminescence (PL) emission of BaZrO(3) assembled nanoparticles at room temperature. The defect created in the nanocrystals and their resultant electronic features lead to a diversification of electronic recombination within the BaZrO(3) band gap. Its optical phenomena are discussed in the light of photoluminescence emission at the green-yellow region around 570 nm.