Piezoelectric nanobeams having circular, rectangular and hexagonal cross-sections are synthesized and used in various Nano structures; however, piezoelectric nanobeams with hexagonal cross-sections have not been studied in detail. In particular, the physical mechanisms of the surface effect and the role of surface stress, surface elasticity and surface piezoelectricity have not been discussed t...

In this introductory exploration of the title theme, we treat a positron as a light nucleus and work within the quasimolecule approximation to obtain, for the first time, adiabatic potential energy curves for its scattering by the He atom. We then show that different elastic and inelastic processes that contribute to the total scattering cross section can be rationalized in molecular terms as d...

Electronic Structure Theory describes the motions of electrons in atoms or molecules. Generally this is done in the context of the Born-Oppenheimer Approximation, which says that electrons are so much lighter (and therefore faster) than nuclei that they will find their optimal distribution for any given nuclear configuration. The electronic energy at each nuclear configuration is the potential ...

for the quintet state of the O2„ 3 g − ...–O2„ 3 g − ... dimer Massimiliano Bartolomei, Estela Carmona-Novillo, Marta I. Hernández, José Campos-Martínez, and Ramón Hernandez-Lamoneda Instituto de Matemáticas y Física Fundamental, Consejo Superior de Investigaciones Científicas, Serrano 123, 28006 Madrid, Spain Centro de Investigaciones Químicas, Universidad Autónoma del Estado de Morelos, 62210...

The literature on gas phase nucleophilic substitution reactions at aliphatic carbon has been reviewed. The emphasis has been on journal articles published in the period 1990–2001. The present review outlines our current understanding of concepts such as potential energy surfaces, structure–energy relationships, microsolvation, and dynamical and mechanistic details based on both experimental and...

We report second and third virial coefficients for the system CO2-H2O, calculated via cluster integrals using quantitative molecular models taken from the literature. Considered models include (1) fits to highly accurate ab initio calculations of the potential energy surfaces, and (2) semi-empirical Gaussian Charge Polarizable Models (GCPM). Three-body effects are found to be essential for obta...

In this study, the theoretical calculations of CO dissociation were carried out on Cu-Fe alloy surface by a full-potential method, which made more accurate results especially on the prediction of adsorption energies. This process may be governed by either a direct route or a H-assisted via HCO and COH intermediates pathways. In comparison to the pure surface Fe (100), the presence of Cu atom en...