Calculations based on density functional theory demonstrate the occurrence of local deformations of the perfect honeycomb lattice in nanographenes to form arrangements, with triangular symmetry, composed of six-membered ring patterns. The formation of these locally regular superstructures, which can be considered as benzenoid-like domains on the 2D graphene lattice, is ascribed to the gain in r...

The reaction between niobium atom and acetaldehyde has been investigated with a DFT approach. Both ground and excited state potential energy surfaces are investigated in detail. The present results show that the title reaction starts with the formation of a η-CH3CHO-metal complex followed by C−C, aldehyde C−H, methyl C−H and C−O bond activation. These reactions can lead to several different pro...

We report an investigation of the structural, morphological, ac-dc electrical, magnetic, and Mössbauer spectroscopy properties 20MnFe2O4-80SiO2 nanocomposite prepared using a one-step facile auto-combustion approach. XRD pattern shows formation MnFe2O4 nanocrystallite without any crystallization SiO2 phase. However, presence secondary phase nanosized α-Fe2O3 particles was also detected. The mor...

The weak and electromagnetic radiative baryon decays of octet T8, decuplet T10, single charmed antitriplet Tc3 sextet Tc6, heavy bottomed Tb3 Tb6 are investigated by using the SU(3) flavor symmetry irreducible representation approach. We analyze contributions from a quark transition q1 → q2γ W exchange transitions find that amplitudes could be easily related in Tb3,b6, Tc3,c6, T10 as well T8γ d...

Theoretical calculations of structural parameters, 57Fe, 14N and 17 O electric field gradient (EFG) tensors for full size-hemin group have been carried out using density functional theory. These calculations are intended to shed light on the difference between the geometry parameters, nuclear quadrupole coupling constants (QCC), and asymmetry parameters (eta Q) found in three spin states of hem...

In this work, we analyze a series of o-hydroxyaryl aldehydes to discuss the interrelation between the resonance-assisted hydrogen bond (RAHB) formation and the aromaticity of the adjacent aromatic rings. As compared to the nonaromatic reference species (malonaldehyde), the studied compounds can be separated into two groups: first, the set of systems that have a stronger RAHB than that of the re...

The reactions of FeO(+) with H2, D2, and HD were studied in detail from 170 to 670 K by employing a variable temperature selected ion flow tube apparatus. High level electronic structure calculations were performed and compared to previous theoretical treatments. Statistical modeling of the temperature and isotope dependent rate constants was found to reproduce all data, suggesting the reaction...

Exotic hadrons are important because their existence or absence can provide important clues to understanding how QCD makes hadrons from quarks and gluons. The first experimentally confirmed exotic will be the first hadron containing both qq and q̄q pairs and the first hadron containing color sextet and color octet pairs. Theoretical models are not very useful because there is no accepted model f...