The conformational analysis of the organic compounds specially the biologically active natural products has attracted the consideration of different research groups. Therefore, in the present study the MP2/6-311+g(d,p)//B3LYP/6-311+g(d,p) level of theory was used to study the conformations of dapdiamide D. The identity of interactions in selected conformers was studied using atom in molecule ap...

the physical adsorption of hydrogen sulfide and carbon dioxide gases on the zigzag (5,0) carbon nanotubes doped with nitrogen was investigated through the application of b3lyp/6-31g* at the level of theory on gaussian 03 software. a variety of stable and high abundance structures of nitrogen doped carbon nanotubes were considered in order to study the interaction between the mentioned gases in ...

having conducted fundamental projects, scientists have expressed their hope to develop the use of carbon nanotubes to release drugs. it is important to release drugs in cell without damaging healthy cells of tissues under study. researchers have shown the fact that nanotubes can perform this function perfectly. to this objective, in the present study the interactions between four anti-cancer dr...

stabilities and quantum molecular descriptors of cyclophoshphamide (an anticancer drug)-functionalized (8,0) zigzag and (4,4) armchair carbon nanotubes (cnts) complexes in water were studied using density functional theory (dft) calculations. two attachments namely the sidewall- and tip-attachments are considered for the model constructions. calculations of the total electronic energy (et) and ...

the main purpose of this research is to investigate computationally the tautomeric reaction pathway of 5-methyl-3-methylthio-1,2,4-triazole from the thermodynamical and mechanistical viewpoints. in this respect, density functional theory (dft) in conjunction with the quantum theory of atoms in molecule (qtaim) has been employed to model the energetic and electronic features of tautomeric mechan...

Coupled cluster methods are considered among the most accurate tools in electronic structure theory. Nonetheless relatively limited attempt seems to have been made to extend their applicability to the description of the core-excitation phenomena that are behind largely used spectroscopic techniques like x-ray absorption spectroscopy and x-ray circular dichroism. As a first step to redeem for su...

The electronic and structural properties of pristine and carbon doped (C-doped) boron nitride nano-ribbons(BNNRs) have been studied employing density functional theory (DFT) calculations. Total energies, gapenergies, dipole moments, and quadrupole coupling constants (qcc) have been calculated in the optimizedstructures of the investigated BNNRs. The results indicated that the stability and gap ...

This work presents a theory to unify the two independent theoretical frameworks of Kohn-Sham (KS) density functional (DFT) and reduced matrix (RDMFT). The generalization KS orbitals hypercomplex number systems leads (HCKS) theory, which extends search space for in KS-DFT that is equivalent natural spin with fractional occupations RDMFT. Thereby, HCKS able capture multi-reference nature strong c...

The molecular structure of the stable conformation of phosphonic acid in gas phase has beencomputed by employing complete geometry optimization in Density Functional Theory(DFT) methods. The methods used for calculations are B3LYP, BP86 and B3PW91 that havebeen studied in two series of basis sets: D95** and 6-31+G(d,p) for hydrogen and oxygenatoms; LANL2DZ for phosphorus. Bond lengths and angle...