using different DFT methods including B3LYP/6-31G(d), VWN/6-31G(d), PBE/TZP and PBE/6-31G(d) shows that, contrary to C60 , which prefers D5d symmetry, the ground state of B80 + adopts S6 point group symmetry. A D3d structure is identified as a saddle point among the S6 minima of B80 . The distortion of D3d to S6 in B80 + is attributed to a superposition of Jahn–Teller and pseudo-Jahn–Teller eff...

In this paper, the structural properties of the B30N20 molecule have been investigated at B3LYP/6-31G (d) level of theory. The optimized structure and electronic properties calculations for the studiedmolecule have been performed using Gaussian 03 program. A mathematical equation of third degreewas exploited for the correlation and exchange energy with the number of primitives. The NaturalBondi...

in this paper, the structural properties of the b30n20 molecule have been investigated at b3lyp/6-31g (d) level of theory. the optimized structure and electronic properties calculations for the studiedmolecule have been performed using gaussian 03 program. a mathematical equation of third degreewas exploited for the correlation and exchange energy with the number of primitives. the naturalbondi...

Mercaptopurine is a medicine used to prevent the formation and spread of cancer cells. Mercaptopurine, known chemically as 1,7-dihydro-6H-purine-6-thione, is an analogue of the purine bases adenine and hypoxanthine. This work reports an investigation of anticancer drug Mercaptopurine with the combined density functional theory and Its structure were optimized at B3LYP/6-31G*, level and The mole...

Recent progress has been made in the reductive debromination of polybrominated diphenyl ethers (PBDEs) by nanoscale zero-valent iron (nZVI). To better understand the mechanism of this reaction, seven selected BDE congeners and their anions were investigated at the density functional theory (DFT) level using four different methods, including B3LYP/6-31G(d), B3LYP/6-31+G(d), B3LYP/6-31G(d,p) and ...

enzymes catalyze many biological reactions. the rates of chemical reaction in the presence ofenzymes are, in some cases, accelerated more than 10 orders of magnitude relative to thecorresponding rates in solution.in this paper a comparison between optimized structures of two enzyme molecules in aspect ofenergy and dipole moment in different conditions including presence of metallic ion, without...

Different lipase enzymes have been tested in order to perform regioselective acetylations on the eudesmane tetrol from vulgarin. High yields (95%) of 1,12-diacetoxy derivative (4) were achieved in 1 h with Candida antarctica lipase (CAL). However, only the 12-acetyl derivative (6) was obtained in similar yield with Mucor miehei (MML) or Candida cylindracea (CCL) lipases. The enzymatic protectio...

The electronic and geometric structures of endo,endo-tetracyclo[4.2.1.1.0] dodeca-4,9-diene(TTDD) molecule have been investigated by ab initio and DFT/B3LYP methods with the 6-31G* and 6-311G* basis sets. The double bonds of TTDD molecule have been endo-pyramidalized. The structure of π-orbitals and their mutual interactions for TTDD molecule have been investigated. The cationic intermediates a...

To elucidate microscopic details of proton cancer therapy (PCT), we apply the simplest-level electron nuclear dynamics (SLEND) method to H+ + (H2O)1-6 at ELab = 100 keV. These systems are computationally tractable prototypes to simulate water radiolysis reactions-i.e. the PCT processes that generate the DNA-damaging species against cancerous cells. To capture incipient bulk-water effects, ten (...