Accurate quantum chemical computations based on density functional theory (DFT) were performed on the series of 2-(4-(naphthalen-2-yl)-1,2,3-thiadiazol-5-ylthio)-N-acetamide (TTA) derivatives. The local reactivity of the acetamide derivatives as anti-HIV drugs were studied in terms of Fukui functions in the framework of DFT. The results based on the basis set superposition error (BSSE) correcti...

The quantum transport computations have been carried on four different width of zigzag graphene using a nonequilibrium Green’s function method combined with density functional theory. The computed properties are included transmittance spectrum, electrical current and quantum conductance at the 0.3V as bias voltage.  The considered systems were composed from one-layer graphene sheets differing w...

Polymer 6, ([trans-Pt(PBu3 )2 (C≡C)2 ]-[Ir(dFMeppy)2 (N^N)](PF6 ))n , (([Pt]-[Ir](PF6 ))n ; N^N = 5,5'-disubstituted-2,2'-bipyridyl; dFMeppy = 2-(2,4-difluoro-phenyl)-5-methylpyridine) is prepared along with model compounds. These complexes are investigated by absorption and emission spectroscopy and their photophysical and electrochemical properties are measured and compared with their corresp...

The di-heme protein Pseudomonas stutzeri cytochrome c(4) (cyt c(4)) has emerged as a useful model for studying long-range protein electron transfer (ET). Recent experimental observations have shown a dramatically different pattern of intramolecular ET between the two heme groups in different local environments. Intramolecular ET in homogeneous solution is too slow (>10 s) to be detected but fas...

Internal rotations of the methyl group in ortho-substituted and 2,6-disubstituted toluenes in their ground state have been investigated by means of various ab initio quantum chemistry methods. Computed barriers at the Hartree-Fock (HF) level using medium sized basis sets agreed reasonably with experimental results in the case of the studied ortho-substituted toluenes. However, this agreement wo...

The problem of phase stability calculation (and crystal structure prediction) is a fundamental problem in materials research and development, and it is typically addressed with highly accurate quantum mechanical computations on a large set of candidate structures, but has limited predictive power. To allow fast prediction of crystal structures, two concepts, usual suspect structure database and...

We have performed reference quantum-chemical calculations for about 130 structures of adenine dimers in stacked conformations, with special attention given to dimers that are either vertically compressed (parallel structures) or contain close interatomic contacts (non-parallel structures). Such geometries are sampled during thermal fluctuations of nucleic acids and contribute to the local confo...

A set of density functional theory (DFT) calculations were performed on 2-carboxamide-1,4- di-N-oxide quinoxaline (2CdNOQ) derivatives. The optimized structure of these compounds in three forms was obtained. Some electronic parameters including dipole moment (μ),ionization potential (I), electron af finity (A), LUMO energy (εLUMO), HOMO energy (εHOMO),electronegativity (χ), hardness (η), ele...

Single ion solvation free energies are one of the most important properties of electrolyte solutions and yet there is ongoing debate about what these values are. Only the values for neutral ion pairs are known. Here, we use DFT interaction potentials with molecular dynamics simulation (DFT-MD) combined with a modified version of the quasi-chemical theory (QCT) to calculate these energies for th...