A collection of new approaches to building and training neural networks, collectively referred to as deep learning, are attracting attention in theoretical chemistry. Several groups aim to replace computationally expensive ab initio quantum mechanics calculations with learned estimators. This raises questions about the representability of complex quantum chemical systems with neural networks. C...

Molecular Dynamics (MD) simulation and Density Functional Theory (DFT) methods have been used to evaluate the efficiency of four quinoline derivatives on corrosion inhibition in the aqueous phase. Some quantum chemical parameters such as hardness (η), electrophilicity (w), polarizability (a), energy of the highest occupied molecular orbital (EHOMO), energy of th...

The effect of impurities on quantum chemical parameters of single-walled nanotubes (SWNTs) was studied using density functional theory (DFT). The density of states (DOS), Fermi energy and thermodynamic energies of (5,5) carbon nanotubes were calculated in the presence of nitrogen impurity. It was found that this nanotube remains metallic after being doped with one nitrogen atom. The partial den...

The structural and energetic characteristics of O3–H2O complexes have been investigated by means of B3LYP, MP2, MP4(SDTQ), CCSD(T) and QCISD(T) methods in conjunction with the AUG-cc-pVDZ and AUG-cc-pVTZ basis sets. Six conformers were found for the O3–H2O complex. Two different intermolecular interactions were expected to participate in the formation of complexes, namely conventional O∙∙∙H hyd...

In this study, the role of interaction of pi electrons on the strength of simultaneous σ-hole interactions (pnicogen, chalcogen and halogen bonds) is investigated using the quantum chemical calculations. X-ben||TAZ∙∙∙Y1,Y2,Y3 complexes (X = CN, F, Cl, Br, CH3 , OH and NH2, TAZ= s-triazine and Y1,Y2 and Y3 denotes PH2F, HSF, and ClF molecules) is introduced as a model. The results show that inte...

The basics of quantum mechanics and statistical thermodynamics were used to predict the potential energy and intermolecular forces of asphaltene molecules. The parameters associated with the chemical structure were also estimated for a specific asphaltene molecule to predict the Mie potential function. Based on the structural results, a new form of the Virial EOS with Peneloux correction wa...

We describe a procedure for the generation of chemically accurate computer-simulation models to study chemical reactions in the condensed phase. The process involves (i) the use of a coupled semiempirical quantum and classical molecular mechanics method to represent solutes and solvent, respectively; (ii) the optimization of semiempirical quantum mechanics (QM) parameters to produce a computati...

over the past decade, the chemical behavior of flavonoids as antioxidants has become the subject ofintense experimental research. in this paper, we use a quantum-chemical approach to shed light on thereactivity of four poly phenols, benzoic acid, vanilic acid, gallic acid and flavone . in order to establishthe most efficient theoretical methodology, different methods, either hartree—fock-based ...

In the present work, the quantum theoretical calculations of the molecular structure of the 1-(1, 3-Benzothiazol-2-yl)-3-(thiophene-5-carbonyl) thiourea has been predicted and are evaluated using Density Functional Theory (DFT) in gas phase. The geometry of the title compound was optimized by B3LYP/6-311+G and B3LYP/6-311+G* methods and the experimental geometrical parameters of the title compo...