Browsing by Author "Voronkov, Eugene O."
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Item Accurate Calculations of Dynamic First Hyperpolarizability: Construction of Physically Justified Slater-Type Basis Sets(John Wiley and Sons Inc., 2014) Rossikhin, V.; Voronkov, Eugene O.; Okovytyy, Sergiy I.; Sergeieva, T.; Kapusta, K.; Leszczynski, Jerzy; Voronkov, Yevgeniy O.EN: An efficient procedure for construction of physically rationalized Slater-type basis sets for calculations of dynamic hyperpolarizability is proposed. Their performance is evaluated for the DFT level calculations for model molecules, carried out with a series of functionals. Advantages of new basis sets over standard d-aug-cc-pVTZ and recently developed LPOL-(FL,FS) Gaussian-type basis sets are discussed. © 2014 Wiley Periodicals, Inc.Item Accurate Calculations of Second-Order Electric and Magnetic Properties: Two Ways of Physically Justified Modifications of Basis Sets(Elsevier B.V., 2010) Bolshakov, V.; Rossikhin, V. V.; Voronkov, Eugene O.; Voronkov, Yevgeniy O.; Okovytyy, Sergiy I.; Leszczynski, JerzyEN: Second-order electric and magnetic properties calculated using an approach based upon the simultaneous analytical dependence of the bond order matrix and basis set functions on the corresponding perturbation parameters have been obtained and analyzed for a series of organic molecules. Various methods of selection of basis set quality for different atoms in investigated molecules were examined in conjunction with calculations of 1H NMR chemical shifts. Comparison of the results obtained at different levels of theory (HF, DFT, MP2) demonstrates small correlation effects for polarizability and magnetic susceptibility while the electron correlation effects play crucial role for calculations of nuclear magnetic shielding (chemical shifts).Item Adsorption of Co, Ni, Cu, Zn Metal Ions on Fullerene C60 and on Single-Wall Carbon Nanotubes C48 as a Driven Force of Composite Coatings’ Electrodeposition(Oles Honchar Dnipro National University, 2021) Tytarenko, Valentina V.; Shtapenko, Eduard Ph.; Voronkov, Eugene O.; Vangara, Aruna; Zabludovsky, Vladimir A.; Kolodziejczyk, Wojciech; Kapusta, Karina; Okovytyy, Sergiy I.EN: Composite electrodeposited films fabricated from aqueous solution of electrolytes that contain ions of metals along with carbon nanomaterial particles such as fullerene C60 were investigated. Results for the cathodic polarization curve showed an increase in charge-transfer resistance. Phase composition analysis for metal films revealed the presence of carbon nanoparticles (CNPs) inside the metal matrix and significant changes in the crystal lattice. As it shown on microphotographies, addition of CNPs changes columnar growth patterns of metallic films to microlayered structure due to passivation of the surface. Density Functional Theory was used for calculation of thermochemical, electronic and structural properties of metal ions complexes with CNPs. Calculated binding energies of the CNPs-Me2+ complexes suggests that an adsorption of Co2+, Ni2+, Cu2+, and Zn2+ ions on the surface of fullerene C60 and SWNT C48 is possible and thermodynamically favorable. Binding affinity was found to be significantly stronger when the metal ion was adsorbed onto a surface of SWNT C48, than adsorption to the fullerene C60. With Cu2+ complexes being the most thermodynamically stable, binding affinities were increasing in a row Co2+Item Calculation of Energy and Magnetic Susceptibility of Fe Atomic System During Dislocation Motion in Magnetic Field(Emerald Group Publishing Ltd, United Kingdom, 2021) Kraiev, Maksym; Voronkov, Eugene O.; Kraieva, VioletaENG: Purpose – The purpose is to calculate the change in the total energy of a small fragment of an idealized lattice of iron (in its pure form and with impurity atoms) containing an edge dislocation during its elementary motion at one interatomic spacing, both under the influence of a constant magnetic field and without it. The introduction of a magnetic field into the system is aimed at checking the adequacy of the description of the phenomenon of magnetoplasticity by changing the total energy of the atomic system. Design/methodology/approach – The design procedure is based on a quantum-mechanical description of the switching process of the covalent bond of atoms in the dislocation core. The authors used the method of density functional theory in the Kohn-Shem version, implemented in the GAUSSIAN 09 software package. Using the perturbation theory, the authors modeled the impact of an external constant magnetic field on the energy of a system of lattice atoms. Findings – The simulation results confirmed the effect of an external constant magnetic field on the switching energy of the covalent bond of atoms in the dislocation core, and also a change in the magnetic susceptibility of a system of atoms with a dislocation. This complements the description of the magnetoplastic effect during the deformation of metals. Originality/value – The authors created quantum-mechanical models of the dislocation motion in the Fe crystal lattice: without impurities, with a substitutional atom Cr and with an interstitial atom C. The models take into account the influence of an external constant magnetic field.Item Novel Physically Adapted STO##-3G Basis Sets. Efficiency for Prediction of Second-Order Electric and Magnetic Properties of Aromatic Hydrocarbons(John Wiley & Sons, Inc., 2012) Voronkov, Eugene O.; Voronkov, Yevgeniy O.; Rossikhin, V. V.; Okovytyy, Sergiy I.; Shatckih, A.; Bolshakov, V.; Leszczynski, JerzyEN: Efficient scheme for construction of physically justified STO##-3Gel and STO##-3Gmag basis sets has been proposed. It is based upon the analysis of analytical form of the first-order correction functions to unperturbed STO basis sets under the perturbation by electric or magnetic fields. The test calculations of polarizability, magnetic susceptibility and chemical shifts performed for a series of aromatic compounds within the developed basis set in the framework of Hartree-Fock and Density Functional Theory (DFT) approaches show good agreement of the predicted properties with experiments.Item Quantum Mechanical Approach for Determining the Activation Energy of Surface Diffusion(Физико-технический институт им. А.Ф. Иоффе Российской академии наук, Санкт-Петербург, 2020) Shtapenko, Eduard Ph. ; Tytarenko, Valentyna V.; Zabludovsky, Volodymyr O.; Voronkov, Eugene O.ENG: A quantum mechanical approach was proposed to determine the activation energy of surface diffusion for copper, nickel, zinc and iron atoms adsorbed on a copper substrate during electrocrystallization for various overvoltages of the substrate. The activation energy of surface diffusion was calculated from the crystal total energy. An increase in the activation energy of surface diffusion with increasing surface potential is associated with an increase in the binding energy between the ad-atom and the substrate.Item Quantum-Mechanical Methodology for Determining the Temperature Dependence of Contact Angle in Melt–Solid Metal Systems(Oles Honchar Dnipro National University, Dnipro, 2024) Shtapenko, Eduard Ph.; Syrovatko, Yuliya V.; Voronkov, Eugene O. ; Mikhailova, Tetiana F.ENG: Aim. In order to determine the composite materials’ manufacturing process parameters, it is necessary to evaluate the stability of their structural components and determine the contact angle of wetting of the filler with the molten binder at the infiltration temperature. The development of a theoretical method for determining the dependence of the contact angle of wetting on temperature in melt – solid metal systems makes it possible to reduce the volume of experimental studies. Methods. The paper presents a quantum mechanical methodology for calculating the binding energy of interacting substances, as well as an experimental study of the dependence of the contact angle on temperature for tin – steel systems. The methodology is based on the calculation of the binding energy between atoms of interacting substances using density functional theory. Results. The calculations show an anomalous behavior of contact angle values for the tin–steel system with increasing temperatures. It means that, when the temperature increases, the values of the contact angle initially become lower, and later, in the temperature range of 450-510 °C, an increase in the contact angle is observed. The obtained theoretical and experimental data correlate well with each other. Conclusions. The appearance of extreme regions in the experimental and theoretical temperature dependences is associated with the thermal expansion of interatomic distances in the crystal lattice. The obtained theoretical and experimental data correlate well with each other and base on the thermal expansion of interatomic distances in the crystal lattice.Item Quantum-Mechanical Modeling of the Interaction between Carbon Nanostructures and Metal Ions(Pleiades Publishing, Ltd, 2021) Tytarenko, Valentyna V.; Shtapenko, Eduard Ph. ; Voronkov, Eugene O.; Zabludovsky, Volodymyr O.; Kolodziejczyk, Wojciech; Kapusta, Karina; Kuznetsov, Vitaliy N.EN: In order to investigate a deposition mechanism, authors have proposed a set of quantum chemical models for formation of fullerene C60 and single-wall carbon nanotubes (SWNTs) C48 metal complexes with Co, Ni, Cu, and Zn. Obtained results proving that adsorption of Co, Ni, Cu, Zn ions on a surface of fullerene C60 and SWNT C48 from the aqueous solution of electrolytes is possible with formation of stable metal-doped carbon nanoparticle complexes. Minimum energy complexes of C60-Co and C60-Cu have corresponded to the structure where ion is located above the center of C6 cell. Meanwhile, C60-Ni complex reach a minimum energy when ion is above the middle of a C-C bond, and for C60-Zn complex the most stable conformation is the one when ion is upon the carbon atom. All the optimized structure for metal complexes with C48 has shown ions been located above the C6 cell’s center.