In this research, Quantum-mechanical calculations were performed at the HF method with the 6-31+G*basis set and at the B3LYP method with the 6-31+G* basis set in the gas phase and five solvents such as water, DMSO, methanol, ethanol and dichloromethane at six temperatures. According to these theoretical results of IR, we extracted thermo chemical parameters such as enthalpy (∆H Kcal/mol), Gibbs...

In this research, Quantum-mechanical calculations were performed at the HF method with the 6-31+G*basis set and at the B3LYP method with the 6-31+G* basis set in the gas phase and five solvents such as water, DMSO, methanol, ethanol and dichloromethane at six temperatures. According to these theoretical results of IR, we extracted thermo chemical parameters such as enthalpy (∆H Kcal/mol), Gibbs...

Semiempirical orthogonalization-corrected methods (OM1, OM2, and OM3) go beyond the standard MNDO model by explicitly including additional interactions into the Fock matrix in an approximate manner (Pauli repulsion, penetration effects, and core-valence interactions), which yields systematic improvements both for ground-state and excited-state properties. In this Article, we describe the underl...

In this research at the first Enalapril drug and its fullerene derivative were optimized. NBO calculations and NMR for the complexes were carried out at the B3LYP/6-31G* quantum chemistry level. Different parameters such as energy levels, the amount of Chemical Shift in different atoms, the amount of HOMO/LUMO, chemical potential (µ ), chemical hardness (η), the coefficients of hybrid bonds (π,...

In this research at the first 2-amino-3-(3,4-dihydroxyphenyl) propanoic aciddrug  drug and its fullerene derivative were optimized. NBO calculations and NMR for the complexes were carried out at the B3LYP/6-31G*quantum chemistry level. Different parameters such as energy levels, the amount of Chemical Shift in different atoms, the amount of HOMO/LUMO, chemical potential (µ ), chemical hardness ...

In this paper, quantum chemical parameters at density functional theory (DFT) B3LYP/6-31G** (d,p) level of theory were calculated for three organic corrosion inhibitors [N-benzoyl-N-(p-aminophenyl) thiourea, N-benzoyl-N-(thiazole) thiourea and N-acetyl-N-(dibenzyl) thiourea. The calculated molecular descriptors such as the HOMO, LUMO, dipole moment, chemical potential (μ), chemical hardness (ղ)...

We investigate possible improvements in the accuracy of semiempirical quantum chemistry (SQC) methods through the use of machine learning (ML) models for the parameters. For a given class of compounds, ML techniques require sufficiently large training sets to develop ML models that can be used for adapting SQC parameters to reflect changes in molecular composition and geometry. The ML-SQC appro...

In this research at the first fluoxetine drug and its fullerene derivative were optimized. NBO calculations and NMR for the complexes were carried out at the B3LYP/6-31G*quantum chemistry level. Different parameters such as energy levels, the amount of Chemical Shift in different atoms, the amount of HOMO/LUMO, chemical potential (µ ), chemical hardness (η), Thermodynamic Properties was determi...

Modern density-functional methods for the calculation of electronic g-tensors have been implementedwithin the framework of the deMon code. All relevant perturbation operators are included. Particular emphasishas been placed on accurate yet efficient treatment of the two-electron spin-orbit terms. At an all-electronlevel, the computationally inexpensive atomic mean-field approximatio...

Gas phase and aqueous phase quantum chemical calculations for the inhibition efficiency of some substituted Benzothiazole (BTH) and its 2-methyl (MeBTH), 2-amino (ABTH), 2-mercapto (MBTH) and 2-phenyl (PhBTH) as corrosion inhibitors for brass in HClO4 were investigated by means of the AM1, PM6, MNDO and RM1 semi-empirical SCF molecular orbital methods. The calculated quantum chemical parameters...