Photon-induced electronic excitations are ubiquitously observed in organic chromophore. In this context, we present a simple, alternative time-independent DFT procedure, for the computation of single-particle excitation energies, particular, lower bound excited singlet states, which primary interest photochemistry. This takes inspiration from recently developed Becke’s exciton model, where key ...

We report the parametrization of a density functional tight binding method (DFTB3) for copper in a spin-polarized formulation. The parametrization is consistent with the framework of 3OB for main group elements (ONCHPS) and can be readily used for biological applications that involve copper proteins/peptides. The key to our parametrization is to introduce orbital angular momentum dependence of ...

The density functional theory (DFT) method combined with B3LYP and B3PW91 hybrid were utilized for geometrical optimization, vibrational frequencies electronic spectral study. levels of the time dependent-DFT 6–311+G(d, p) basis set have been used to determine highest occupied molecular orbital (HOMO) – lowest unoccupied (LUMO) energies, absorption wavelengths, properties (total energy gap) 4-(...

The ability for density functional theory with the B3LYP lanl2dz basis set to predict 1st (Wave 1) and 2nd 2) reductions of diazine ring in a series thirty-seven (37) 1,4-di-N-oxide quinoxaline-2-carboxamide derivatives dimethylformamide was examined. B3LYP/lanl2dz method had strong correlation low experimental potentials Wave 1 2, respectively. There are nine identifiable analogs based on simi...

Infrared multiple photon dissociation (IRMPD) action spectra of the protonated forms of 2'-deoxyguanosine-5'-monophosphate and guanosine-5'-monophosphate, [pdGuo+H](+) and [pGuo+H](+), are measured over the IR fingerprint and hydrogen-stretching regions using the FELIX free electron laser and an OPO/OPA laser system. Electronic structure calculations are performed to generate low-energy conform...

In this study, a combined quantum mechanical and experimental analyses were performed to investigate crystal structure of the immediate degradation product of TNT, 2-hydroxylamino-4,6-dinitrotoluene (2HADNT) and to reveal its important chemical properties. Leakage of 2-HADNT has caused serious environmental pollution and therefore raises widespread concerns. In the quantum mechanical analysis, ...

A computational modeling of the protonation of corannulene at B3LYP/6-311G(d,p)//B3LYP/6-311G(d,p) and of the binding of lithium cations to corannulene at B3LYP/6-311G(d,p)//B3LYP/6-31G(d,p) has been performed. A proton attaches preferentially to one carbon atom, forming a sigma-complex. The isomer protonated at the innermost (hub) carbon has the best total energy. Protonation at the outermost ...

α-amylase has been studied extensively from various sides. this enzyme is used in many industries .many applications of this enzyme have encouraged us for greater attempts on the study of α-amylase and to search for more effective processes. in this investigation, the structure of nanotube - catalytic site of bacillus subtilis α- amylase was optimized by hyperchem 7.0 and then it was investigat...

amyloid-β (aβ) self-assembly into cross-β amyloidfibrils is implicated in a causative role in alzheimer’s disease pathology.uncertainties persist regarding the mechanisms of amyloid self assembly and the role of metastable prefibrillar aggregates. aβ fibrilsfeature a sheet-turn-sheet motif in the constituent β-strands; as such, turn nucleation has been proposed as a rate-limiting step in the se...