Chemical hardness () and absolute electronegativity () have important applications in chemistry. Inthe conceptual Density Functional theory (DFT), these concepts has been associated with electronicenergy and the relationship with ionization energy (I) and electron affinity (A) of these concepts hasbeen given. In this study, graphical method was used in order to see the relationship with the ato...

In a very recent article (Torrent-Sucarrat et al., J Comput Chem 2007, 28, 574), we have shown how to evaluate the global hardness for polyatomic molecules using a hardness kernel approximation. We present here an extension of this previous work by improving the model used to evaluate the hardness kernel and the Fukui function. In addition, the concept of the local hardness is analyzed in detai...

During the cementation of metallic restorations, the polymerization of dual-curing resin cements depends exclusively on chemical activation. This study evaluated the influence of chemical activation compared with dual-curing (chemical and light activation), on the hardness of four dual-curing resin cements. In a darkened environment, equal weight proportions of base and catalyst pastes of the c...

We propose a systematic method of analyzing pseudopotential transferability based on linear-response properties of the free atom, including self-consistent chemical hardness and polarizability. Our calculation of hardness extends the approach of Teter1 not only by including self-consistency, but also by generalizing to non-diagonal hardness matrices, thereby allowing us to test for transferabil...

In the literature, popular electronic structure principles regarding electronegativity, chemical hardness and electrophilicity concepts are available. It is undeniable that the equalization principles related to reactivity indexes such as electronegativity, hardness, and electrophilicity have been widely used to calculate the partial charges of atoms in a molecule. It is apparent that all such ...

In this research at the first, captopril drug (CA) and its fullerene connected form (FCA) wereoptimized. Natural Bond Orbital (NBO) calculations for these compounds were carried out at theB3LYP/6-31G quantum chemistry level, in the gas phase and the liquid phase. These calculations canbe performed at different accuracy levels depending on the aim of the theoretical study [1]. Forinstance, Densi...

despite having some useful properties, stainless steels suffer from lack of suitable surface hardness. in this research electroless ni-b-tl coating was used with the aim to increase their surface hardness. the effects of nickel chloride, sodium borohydride, thallium nitrate and ethylendiamin on the chemical composition of coating were studied. to achieve an increase in hardness, the effects of ...

Dynamic behaviors of chemical concepts in density functional theory such as frontier orbitals (HOMO/LUMO), chemical potential, hardness, and electrophilicity index have been investigated in this work in the context of Bohn-Oppenheimer quantum molecular dynamics in association with molecular conformation changes. Exemplary molecular systems like CH5 , Cl (H2O)30 and Ca 2+ (H2O)15 are studied at ...

This study evaluated, using Knoop hardness test, the polymerization depth of Rely-X dual-cured resin cement activated by chemical reaction alone (control group) or by chemical/physical mode with light curing through a 1.5-mm-thick ceramic layer (HeraCeram). Bovine incisors had their buccal surface flattened and hybridized. On this surface, a rubber mould (5 mm diameter; 1 mm high) was bulk fill...