Double-layers sDLsd were observed in the expanding region of an inductively coupled plasma with Ar–SF6 gas mixtures. No DL was observed in pure argon or SF6 fractions below a few percent. They exist over a wide range of power and pressure although they are only stable for a small window of electronegativity stypically between 8% and 13% of SF6 at 1 mTorrd, becoming unstable at higher electroneg...

The concept of atomic point charges is well established in theoretical chemistry. Atomic point charges have played an important role in understanding and modeling chemical behavior by allowing to extract and quantify information stored in the molecular electron distribution of chemical compounds. Thus, atomic point charges have been used to estimate reactivity indices, dissociation constants, p...

The entha lpy AH of general d isplacement react ions A B + C D A D + C B is der ived w i t h the a id of the ion ic app rox ima t i on to chemica l bond ing . T h i s entha lpy compares favourab ly w e l l w i t h Pau l ing 's cor responding equat ion AH—— 46 (%B— ̂ d ) (%A — XC)These expressions are used as a basis to discuss var ious aspects of chemical r eac t i v i t y : reversals i n react ...

Assigning effective atomic charges that properly reproduce the electrostatic fields of molecules is a crucial step in the construction of accurate interatomic potentials. We propose a new approach to calculate these charges, which as previous approaches are, is based on the idea of charge equilibration. However, we only allow charge to flow between covalently bonded neighbors by using the conce...

A scalable parallel algorithm has been designed to perform multimillion-atom molecular dynamics (MD) simulations, in which first principlesbased reactive force fields (ReaxFF) describe chemical reactions. Environment-dependent bond orders associated with atomic pairs and their derivatives are reused extensively with the aid of linked-list cells to minimize the computation associated with atomic...

Atomic-scale gold clusters were intercalated at the inter-facet corner sites of Pt-shell Ru-core nanocatalysts with near-monolayer shell thickness. We demonstrated that these unique clusters could serve as a drain of valence electrons in the kink region of the core-shell heterojunction. As jointly revealed by density functional theory calculations and valence band spectra, these Au clusters ext...

We study the role of electronegativity in sliding friction for five different two-dimensional (2D) monolayer systems using ab initio calculations within density functional theory with van der Waals corrections. show that depends strongly on involved atoms' difference. All studied exhibit almost same magnitude force when along nonpolar path, independent material and surface structures. In contra...

An interatomic potential model has been developed for molecular-dynamics simulations of TiO2 ~rutile! based on the formalism of Streitz and Mintmire @J. Adhes. Sci. Technol. 8, 853 ~1994!#, in which atomic charges vary dynamically according to the generalized electronegativity equalization principle. The present model potential reproduces the vibrational density of states, the pressure-dependen...

Recent interest in the growth of GaAs1-xBix semiconductor alloys with controlled Bi concentration has been stimulated by the sensitivity of the bandgap energy and valence band structure to Bi concentration, x. These sensitivities offer the possibility to engineer both the band gap and band offsets at junctions to improve the performance of devices. Realization of this potential, however, requir...

The electronegativity equalization method is classically used as a method allowing the fast generation of atomic charges using a set of calibrated parameters and provided knowledge of the molecular structure. Recently, it has started being used for the calculation of other reactivity descriptors and for the development of polarizable and reactive force fields. For such applications, it is of in...