Several DFT functionals have been carried out to study the first hyperpolarizabilities βHRS of push-pull polyene as a function basis sets, electron correlation, size, frequency dispersion and geometry. These calculations confirm huge effects Møller– Plesset (MP2) results reproduces values hyperpolarizability obtained with reference CCSD(T) level. Among density functional theory exchange- correl...

A linear regression correction approach has been developed successfully to account for the electron correlation energy missing in Hartree-Fock calculation and to reduce the calculation errors of density functional theory. The numbers of lone-pair electrons, bonding electrons and inner layer electrons in molecules, and the number of unpaired electrons in the composing atoms in their ground state...

A linear regression correction approach has been developed successfully to account for the electron correlation energy missing in Hartree–Fock calculation and to reduce the calculation errors of density functional theory. The numbers of lone-pair electrons, bonding electrons and inner layer electrons in molecules, and the number of unpaired electrons in the composing atoms in their ground state...

structural and magnetic properties of purine and pyrimidine nucleotides (cmp, ump, dtmp, amp, gmp, imp) were studied at different levels of ab initio molecular orbital theory. these calculations were performed at the hartree-fock level and density functional b3lyp methods. geometries were fully optimized by following cs symmetry restrictions. the standard 6-31g** basis set which includes polari...

in this work, we report results of calculations based on the density functional theory of different species metal-ozone, containing mercury, silver and gold. the chosen species range from small molecules and large transition-metal containing ozone with mercury, silver and gold complexes. a comparative analysis of the description of the metal-oxygen bond obtained by different methodologies is pr...

Ruthenium complexes have gained significant attention due to ruthenium similarity iron, lower toxicity, and higher anticancer effectiveness than other compounds. In this contribution, five new isonicotinate-polyethylene glycol ester ligands were synthesized characterized by NMR IR spectroscopies. The corresponding Ru(II) also obtained, their structure was elucidated traditional methods. optimiz...

In the present work we investigate the adequacy of broken-symmetry unrestricted density functional theory for constructing the potential energy curve of nickel dimer and nickel hydride, as a model for larger bare and hydrogenated nickel cluster calculations. We use three hybrid functionals: the popular B3LYP, Becke's newest optimized functional Becke98, and the simple FSLYP functional (50% Hart...

The quantum chemical method is employed to study the modified asymmetric allylation of benzaldehyde controlled by diisopropyl D-(-)-tartrate auxiliary. All the structures are optimized completely at the B3LYP/6-31G(d,p) level. The (R)-secondary alcohol can be achieved mainly through a six-membered ring chair-like transition state structure. From the relative reaction rates theory the main produ...

Density functional theory method at the level of B3LYP/6-31G(d,p) in combination with the polarizeable continuum model have been used to compute one-electron oxidation potentials for eighteen N-hydroxy compounds in aqueous solution. Analysis of correlation between the experimental oxidation potentials and the theoretically calculated values revealed that notable relations existed between the ex...

The Gibbs energy of reaction of oxidative addition of ammonia to an iridium complex in diethyl ether was calculated by seven density functional methods, in particular B3LYP, PBE, CAMB3LYP, M05, M06, M06-L, and oB97X. The calculated free energies, based on geometry optimization and frequency calculations in both the gas phase and solution, were compared with the experimental result, 1.3 kcal mol...