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 a...

Two sets of rigorous upper bounds on the atomic ionization potential are derived from some known inequalities of the classical analysis. The first set of bounds are expressed in terms of radial expectation values of the electron density; they improve previously found bounds of the same kind and converge to the exact ionization potential. The other bounds depend on various atomic density functio...

Lattice relaxations, surface phonon spectra, surface energies, and work functions are calculated for Rh(100) and Rh(110) surfaces using density-functional theory and the fullpotential linearized augmented plane wave method. Both, the local-density approximation and the generalized gradient approximation to the exchange-correlation functional are considered. The force constants are obtained from...

We present experimental results on the structure of Ag thin films grown on high-symmetry surfaces of both quasicrystals and approximants. For coverages above ten monolayers, Ag form fcc nanocrystals with (111) plane parallel to the surface plane. Depending on the substrate surface symmetry, the Ag nanocrystals exist in one, two or five different orientations, rotated by a multiple of 2π/30. The...

Approximate wavefunctions can be improved by constraining them to reproduce observations derived from diffraction and scattering experiments. Conversely, charge density models, incorporating electron-density distributions, atomic positions and atomic motion, can be improved by supplementing diffraction experiments with quantum chemically calculated, tailor-made electron densities (form factors)...

The CHIANTI database was described by Dere et al. (1997, hereafter Paper I) and the present paper applies the atomic data to the study of extreme ultraviolet emission lines found in the SERTS-89 active region spectrum published by Thomas & Neupert (1994). Firstly, the emission line ratios that are insensitive to density and temperature are used to check both the quality of the atomic data and t...

Diode-laser absorption tomography is described with which the spatial temperature and the atomic number density distribution of a 3-kW class arcjet can be derived simultaneously by reconstruction of the absorption coefficient field of the arcjet's argon exhaust plume. One can perform various parameter measurements by changing the arcjet's mass-flow rates and discharge currents. The maximum temp...

A simplified molecular orbital (MO) formalism based on density functional theory is developed. Starting from the same energy expression as Kohn-Sham theory the electronic density is expanded in terms of atomic mono-center densities. Application of the variational principle leads to a secular matrix with a particularly transparent structure which allows the definition of a resonance integral tak...

For obtaining reservoir petrophysical properties, for example porosity, non-destructive methods such as X-ray computed tomography, CT, seems to be precise and accurate. Porosity is deducted from the CT image with a single scan via different techniques, such as pore space detection by image segmentation techniques then correlation with porosity. More than one hundred samples with carbonate li...

Ion molecules with general chemical formula as [Li(H2O)] (n=1,2,3), have been chosen as model species toinvestigate the chemical properties of hydrated lithium cations. The RHF(SCVS)/UGBS level of calculationhas been used for obtaining equilibrium geometries and Rho(r) functions (electron density distributions). By theaid of fundamental physical theorems implemented in Quantum Theory of Atoms i...