an interaction potential at different orientation for the ch4 and co2 complex was derived at theb3lyp level of theory and 6-31+g* basis sets. the potential energy surface was computed on somemolecular geometries. the complete basis set limit of the interaction energies were fitted to wellknownanalytical functions. to determine the second virial coefficients b, u(r) is used to obtain themodel’s ...

Quantum chemistry calculations have been performed to compute the optimized geometries, vibrational frequencies, and Mulliken Charges at B3LYP/6-31G(d) and B3LYP/6-311++G(d,p) levels for 3-(4-fluorophenyl)thiophene (FPT), 3-(4-nitrophenyl)thiophene (NPT) and 3-(4-cyanophenyl) thiophene (CPT) in the ground state. In addition, the (13)C and (1)H NMR are calculated by B3LYP/6-311++G(d,p) and B3LYP...

The B3LYP/6-311+G(d)-SDD method, which considers the relativistic effect of bromine, was adopted for the calculations of the selected polybrominated diphenyl ethers (PBDEs) in the present study, in which the B3LYP/6-311+G(d) method was also applied. The calculated values and experimental data for structural parameters of the selected PBDEs were compared to find the suitable theoretical methods ...

The vibrational frequencies and molecular geometry of the title compound are examined theoretically using the density functional theory (DFT) B1LYP, B3LYP, B3P86 and B3PW91 methods. For vibrational frequencies, the correlation coefficients obtained for B1LYP, B3LYP, B3P86, and B3PW91 methods are 0.998, 0.999, 0.998 and 0.998, respectively. B3LYP method provides most satisfactory correlation (CC...

In this paper, we evaluate semiempirical methods (AM1, PM3, and ZINDO), HF and DFT (B3LYP) in different basis sets to determine which method best describes the sign and magnitude of the geometrical parameters of artemisinin in the region of the endoperoxide ring compared to crystallographic data. We also classify these methods using statistical analysis. The results of PCA were based on three m...

Quantum mechanical calculations of energies, geometries and vibrational wavenumbers of 4-nitroaniline (4NA) were carried out by using Density functional theory (DFT /B3LYP/6-311++G(d,p)/ CC-pvdz / Aug-cc-Pvdz) method. The optimized geometrical parameters obtained by B3LYP method show good agreement with experimental X-ray data. The best level of theory in order to reproduce the experimental wav...

Theoretical investigations are performed by DFT method of B3LYP/6-31G+(2d,p) and B3LYP/6-311G+(2d,p) basis sets for three carbonyl thiourea compounds, namely N-[(2,6Diethylphenyl)carbamothioyl]-2,2-diphenylacetamide (Compound I), N-[(3-Ethylphenyl)carbamothioyl]-2,2-diphenylacetamide (Compound II) and 2,2-Diphenyl-N-{[2(trifluoromethyl)phenyl]carbamothioyl}acetamide (Compound III). Theoretical ...