adsorption of nh3 and h2o molecules on pristine and b–doped al12n12 nano–cage was investigated using density functional theory, by means of b3lyp and x3lyp functionals. both nh3 and h2o molecules were found to bind to an al atom of al12n12 via chemisorption, releasing energies ranging from –1.48 to –1.53 and –1.16 to –1.22 ev, respectively. the binding energies of x3lyp functional are somewhat ...

The problem of constructing an orthogonal set of eigenvectors for a DFT matrix is well studied. An elegant solution is mentioned by Matveev in [1]. In this paper, we present a distilled form of his solution including some steps unexplained in his paper, along with correction of typos and errors using more consistent notation. Then we compare the computational complexity of his method with the m...

in this study the chemical properties of b6c4si and c16 clusters connected vitamin c have been investigated using density functional theory (dft). nmr parameters and homo- lumo gap energy are calculated by using density functional method (b3lyp) with 6-311g* basis set. calculations show that homo- lumo gap energy of vitamin c decreases after connecting to b6c4si or c16 cluster decreasing of hom...

a Nearly Tridiagonal Matrix Magdy Tawfik Hanna1 ABSTRACT A fully-fledged definition for the fractional discrete Fourier transform of type IV (FDFT-IV) is presented and shown to outperform the simple definition of the FDFT-IV which is proved to be just a linear combination of the signal, its DFT-IV and their flipped versions. This definition heavily depends on the availability of orthonormal eig...

the term electronegativity .was introduced by linus pauling, who characterized on the basis ofthermodynamic data from the energies of the single bonds. in present study, the density functional theory(dft) was used to calculate electronegativity of atoms. the base of calculation is similar to pauling andmulliken methods. the results indicate that the largest value of electronegativity for fluori...

background: a balanced nutrition schedule provides the essential substances for proper oral health. objectives: the aim of this study was to investigate the association between dental caries and body mass index in 6-11 year-old children in zahedan. materials and methods: in this cross-sectional study 1213 children (670 girls, 543 boys) were included. body mass index (bmi) and clinical examinati...

We propose and consolidate a definition of the discrete fractional Fourier transform that generalizes the discrete Fourier transform (DFT) in the same sense that the continuous fractional Fourier transform generalizes the continuous ordinary Fourier transform. This definition is based on a particular set of eigenvectors of the DFT matrix, which constitutes the discrete counterpart of the set of...

background and aims. childhood obesity has been associated with high refined sugar intake. the relationship between sucrose intake and development of dental caries has been established. the aim of this study was to determine the association between age-specific body mass index (bmi-for-age) and dental caries in children. materials and methods. in this cross-sectional study a total of 1003 child...

DFT reactivity descriptors, the ultraviolet–visible spectra and hydrolysis mechanism of three cationic dyes [Malachite Green (MG), Brilliant (BG) Ethyl (EG)] are performed with several exchange–correlation functional (global GGA, hybrids range-separated). Using time-dependent density theory, theoretical absorption obtained obey trend for λmax: GGA > hybrid range-separated functional. Thanks to ...