It is an understatement to say that the density functional theory (DFT) has strongly influenced the evolution of quantum chemistry during the past 15 years; the term “revolutionalized” is perhaps more appropriate. Based on the famous Hohenberg and Kohn theorems,1 DFT provided a sound basis for the development of computational strategies for obtaining information about the energetics, structure,...

Given a vector space of microscopic quantum observables, density functional theory is formulated on its dual space. A generalized Hohenberg-Kohn theorem and the existence of the universal energy functional in the dual space are proven. In this context ordinary density functional theory corresponds to the space of one-body multiplication operators. When the operators close under commutation to f...

A new mixed  halo chromate  nanoparticle compound was synthesised and characterized. Triphenylphosphonium trifluoroiodochromate (III)[P(C6H5)3H]+[CrF3I]- nanoparticle was synthesized by using triphenylphosphonium  iodide reaction with CrF3, in the presence of  3-mercaptopropionic acid. This method is a simple and direc...

The electroluminescence from PPV and the blue light emission from PPP constitute exciting subjects of study. The band gap of these semiconducting polymers can be engineered in a wide range from red to ultraviolet by structural changes made on them. In the present work, we present a theoretical approach based on semiempirical and ab initio total energy and force calculations of PPV and PPP. We p...

In the search of clean and efficient energy sources intermediate temperature solid oxide fuel cells are among the prime candidates. What sets the limit of their efficiency is the solid electrolyte. A promising material for the electrolyte is ceria. This thesis aims to improve the characteristics of these electrolytes and help provide thorough physical understanding of the processes involved. Th...

the stacking mechanism of the 1h-4h proton transfer in 4-pyridone, 4-pyridinthione and p-aminopyridineare constructed. for quantitative description of this process by means of the quamtumchemicalmethod density functional theory (dft) the activation energy (

Here, new N,N′-dipyridoxyl(4,4''-diaminodiphenylether) Schiff-base ligand has been synthesized and characterized by IR, 1H NMR and mass spectrometry. Also, geometry optimization and theoretical assignment of IR spectrum of the ligand have been computed by employing density functional theory (DFT) method. Two pyridine rings and benzene rings in the bridge region are not in the same plane. The ca...