نتایج جستجو برای: X-ray charge dmicy,Hansen-Coppens formalism

تعداد نتایج: 823220  

Journal: :journal of physical & theoretical chemistry 2010
zahra sharafi

the x-ray charge density analysis of a hydroxynaphthoquinnne derivative was obtained by multipolar hansen-coppens formalism refinement through high resolution x-ray diffraction data at 100(1) k. the molecularproperties of the title compound resulted from the combined experimental and the quantum theory of atoms inmolecules (qtaim) studies. the topological properties of the covalent bonds and of...

Zahra Sharafi

The X-ray charge density analysis of a hydroxynaphthoquinnne derivative was obtained by multipolar Hansen-Coppens formalism refinement through high resolution X-ray diffraction data at 100(1) K. The molecularproperties of the title compound resulted from the combined experimental and the quantum theory of atoms inmolecules (QTAIM) studies. The topological properties of the covalent bonds and of...

2012
N. Ghermani N. Bouhmaida

models [1] of the charge density derived from X-ray experiments are available. Starting with a multipolar model of the valence deformation density, Stewart was the first to give an analytical expression of the electrostatic potential in this case [2]; his first papers are based mainly on reciprocal-space calculations by Fourier transformation of [ H 2 ] ^weighted structure factors. Direct calcu...

Journal: :Acta Crystallographica Section A Foundations of Crystallography 1998

Journal: :Acta crystallographica. Section A, Foundations of crystallography 2001
P Macchi P Coppens

Relativistic wave functions for elements with Z = 37-54 [Su & Coppens (1998). Acta Cryst. A54, 646-652] have been fitted with a linear combination of Slater-type functions as defined by Bunge, Barrientos & Bunge [At. Data Nucl. Data Tables (1993), 53, 113-162], for use in charge-density analysis and other applications. In addition, numerical relativistic wave functions have been calculated for ...

Journal: :Molecules 2015
Mokhtaria Drissi Nadia Benhalima Youcef Megrouss Rahmani Rachida Abdelkader Chouaih Fodil Hamzaoui

This work concerns a comparison of experimental and theoretical results of the electron charge density distribution and the electrostatic potential around the m-nitrophenol molecule (m-NPH) known for its interesting physical characteristics. The molecular experimental results have been obtained from a high-resolution X-ray diffraction study. Theoretical investigations were performed using the D...

Journal: :Acta crystallographica. Section A, Foundations of crystallography 2000
Volkov Gatti Abramov Coppens

The atoms in molecules (AIM) theory may be used to derive atomic charges, atomic volumes and molecular dipole moments from the charge density. The theory is applied to theoretical periodic Hartree-Fock (PHF), density-functional (DFT) and experimental X-ray densities of p-nitroaniline using the program TOPOND and a newly developed program, TOPXD, for topological analysis of densities described b...

Journal: :Acta crystallographica. Section A, Foundations of crystallography 2006
Anatoliy Volkov Harry F King Philip Coppens Louis J Farrugia

Accurate, yet simple and efficient, formulae are presented for calculation of the electrostatic potential (ESP), electric field (EF) and electric field gradient (EFG) from the aspherical Hansen-Coppens pseudoatom model of electron density [Hansen & Coppens (1978). Acta Cryst. A34, 909-921]. They are based on the expansion of |r' - r|(-1) in spherical harmonics and the incomplete gamma function ...

Journal: :iranian journal of chemistry and chemical engineering (ijcce) 2012
behzad sadeghi rasoul sarraf-mamoory hamid reza shahverdi,

limn2o4 spinel cathode materials have been successfully synthesized by solid-state reaction. surface of these particles were modified by nanostructured lifepo4 via sol gel dip coating method. synthesized products were characterized by thermally analyzed by thermogravimetric and differential thermal analysis(tg/dta), x-ray diffraction (xrd), scanning electron microscopy (sem), and energy dispers...

صادقی, بهزاد , صراف ماموری, رسول ,

In this paper, LiMn2O4 spinel cathode materials have been successfully synthesized by solid-state reaction. Surface of these particles modified by nanocoating of LiFePO4.  Synthesized products were characterized by X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), and Energy Dispersive X-ray Spectroscopy (EDX). The results of electrochemical tests showed that charge/discharge ca...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید