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...

Cholesky decomposition of the atomic two-electron integral matrix has recently been proposed as a procedure for automated generation of auxiliary basis sets for the density fitting approximation [F. Aquilante et al., J. Chem. Phys. 127, 114107 (2007)]. In order to increase computational performance while maintaining accuracy, we propose here to reduce the number of primitive Gaussian functions ...

in the present work, the structural and electronic properties, and conductivity of (5,5) and (6,6) single walled carbon nanotubes in the ground state have done by using the hartree-fock and density functional theory dft-b3lyp/6-31g* level. delocalization of charge density between the bonding or lone pair and antibonding orbitals calculated by nbo (natural bond orbital) analysis. these methods a...

We considered the kaon absorption from atomic states into nucleus. We found that the nuclear density probed by the atomic kaon significantly depends on the kaon orbit. Then, we reexamined the meanings of the observed strengths of one–body and two–body kaon absorption, and investigated the effects to the formation spectra of kaon bound states by in–flight (K−, p) reactions. As a natural conseque...

X-ray diffraction patterns from crystals of biological macromolecules contain sufficient information to define atomic structures, but atomic positions are inextricable without having electron-density images. Diffraction measurements provide amplitudes, but the computation of electron density also requires phases for the diffracted waves. The resonance phenomenon known as anomalous scattering of...

The density of atomic systems is analysed via the Single-Exponential Decay Detector (SEDD). SEDD is a scalar field designed to explore mathematical, rather than physical, properties of electron density. Nevertheless, it has been shown that SEDD can serve as a descriptor of bonding patterns in molecules as well as an indicator of atomic shells [P. de Silva, J. Korchowiec, and T. A. Wesolowski, C...

A detailed treatment of a confined relativistic atom, needed as an initial step for the parametrization of the self-consistent-charge density-functional tight-binding method, is presented and discussed. The required one-component quantities, i.e., orbital energies, orbital wave functions, and Hubbard parameters, are obtained by weighted averaging of the corresponding numbers determined for the ...

We describe the joint application of the density matrix renormalization group and canonical transformation theory to multireference quantum chemistry. The density matrix renormalization group provides the ability to describe static correlation in large active spaces, while the canonical transformation theory provides a high-order description of the dynamic correlation effects. We demonstrate th...

The static electric dipole polarizability of NaN clusters with even N has been calculated in a collective, axially averaged and a three-dimensional, finite-field approach for 2 ≤ N ≤ 20, including the ionic structure of the clusters. The validity of a collective model for the static response of small systems is demonstrated. Our density functional calculations verify the trends and fine structu...