in this paper, we used quantum chemical approach to shed light on the catalytic mechanism of γ-carbonic anhydrase (γ-ca) to convert carbon dioxide to bicarbonate ion. density functional theory (dft) using b3lyp and ub3lyp functional and three split-valance including 6-31g*, 6-311g** and 6-311++g** basis sets were used to calculate the details of electronic structure and electronic energy of act...

for analyzing of compositions molecular orbitals in this article in order to combination only- xylometazolin-c7 x2 (xy) and c60– xylometozolin-c65-x2 (fxy), first got energies of highest occupied molecular orbital (homo) and lowest unoccupied molecular orbital (lumo) by using nbo analyze in gaussian 03 software. then, occupancy parameter, gap of energy, and δnmax were calculated   by support of...

palladium (ii) coordination complexes catalyze the reaction of alcohols with ketones to yield ethers. during the catalytic cycle, the alcohol adds selectively to the β-carbon (anti-markovnikov). in this work, mechanism and kinetics for the reaction of methanol with methyl vinyl ketone (mvk), being catalyzed by pd, has been theoretically investigated in detail. using quantum mechanical approach,...

Femtosecond ~fs! dynamics of reactions of cyclic ethers, symmetric and asymmetric structures, are reported. The diradical intermediates and their b-cleavages, which involve simultaneous C-C, C-H s-bond breakage and C-O, C-C p-bond formation, are observed and studied by fs-resolved mass spectrometry. To compare with experiments, we present density functional theory calculations of the potential ...

Density functional theory offers a very accurate way of computing materials properties from first principles. However, it is too expensive for modeling large-scale molecular systems whose properties are, in contrast, computed using interatomic potentials. The present paper considers, from a mathematical point of view, the problem of constructing interatomic potentials that approximate a given q...

Quasiclassical trajectory studies have been performed for the reaction between an H ~or D! atom incident from the gas phase and a H ~or D! atom adsorbed onto a Cu~111! surface. Results from a density functional calculation of the interaction between H and a Cu~111! surface are used to construct a detailed potential energy surface which contains all six nuclear degrees of freedom. Impacts of the...

We investigate the shifts of the core-level binding energies in small gold nanoclusters by using ab initio density-functional-theory calculations. The shift of the 4f states is calculated for magic-number nanoclusters in a wide range of sizes and morphologies. We find a nonmonotonous behavior of the core-level shift in nanoclusters depending on the size. We demonstrate that there are three main...

the interaction of a nitrosyl hydride (hno) molecule with b12n12 nanocage was explored by means of density functional calculations. it was found that hno prefers to be adsorbing on a boron atom of the cage with adsorption energy of -0.65 ev. this adsorption process significantly shifts the homo-lumo gap (eg) of the cage to lower energies, thereby reducing eg of the cage from 6.84 to 2.45 ev. ti...

the structure of fluids confined by planar walls is studied using density functional theory. the density functional used is a generalized form of the hypernetted chain (hnc) functional which contains a term third order in the density. this term is chosen to ensure that the modified density functional gives the correct bulk pressure. the proposed density functional applied to a lennard-jones flu...

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...