Interatomic Potential and Thermodynamic Property of Diatomic Uranium

2012 ◽  
Vol 550-553 ◽  
pp. 2810-2813 ◽  
Author(s):  
Xiu Lin Zeng ◽  
Xue Hai Ju ◽  
Si Yu Xu
Keyword(s):  
Density Functional ◽  
Vibrational Energy ◽  
Interatomic Potential ◽  
Zero Point ◽  
Dft Method ◽  
Basis Set ◽  
Functional Theory ◽  
Lennard Jones ◽  
Anharmonicity Constant ◽  
The Relationship

Potential energy scan for U2 was performed by density functional theory (DFT) method at the B3LYP level in combination with the (ECP80MWB_AVQZ + 2f) basis set. The dissociation energy of U2, after being corrected for the zero-point vibrational energy, is 2.482 eV, which is in good agreement with the experiment. The calculated energy was fit to the typical potential functions of Morse, Lennard-Jones (L-J) and Rydberg. Both the Morse and Rydberg functions are good representatives of the potentials, but the Lennard-Jones function is not. The anharmonicity constant is very small. The anharmonic frequency is 113.99 cm–1. Thermodynamic properties of entropy and heat capacity at 298.2 K – 1500 K were calculated by using DFT-B3LYP computational results and Morse parameters, respectively. The relationship between entropy and temperature was established.

scholarly journals DFT study of new organic materials based on PEDOT and 4-[2-(2-N, N-dihydroxy amino thiophene) vinyl] benzanamine

2021 ◽  
Author(s):  
Côme Damien Désiré Mveme ◽  
Fridolin Tchangnwa Nya ◽  
Geh Wilson Ejuh ◽  
Alhadji Malloum ◽  
Jeanet Conradie ◽  
...  
Keyword(s):  
Organic Solar Cells ◽  
Density Functional ◽  
Vibrational Energy ◽  
Zero Point ◽  
Molecular Geometry ◽  
Basis Set ◽  
Functional Theory ◽  
Light Emitting ◽  
The Density Functional Theory ◽  
Zero Point Vibrational Energy

Abstract In the present study, we theoretically determine the optoelectronic, electronic, nonlinear optical (NLO) and thermodynamic properties of new materials from the conjugated polymer poly (3,4-ethylenedioxythiophene) (PEDOT) doped with halogens (Fluorine and Chlorine) combined with the organic semiconductor 4-[2-(2-N, N-dihydroxy amino thiophene) vinyl] benzamine (DATVB). The molecular geometry of the ground state, the optoelectronics and electronics parameters have been calculated by combining the 6-311++G (d, p) basis set with functionals of the density functional theory (DFT). The functionals B3LYP and the CAM-B3LYP have been used for NLO parameters. The energy gaps obtains for all the compounds are less than 3.0 eV. These results clearly show that PEDOT and its derivatives can be considerated as good semiconductors. They can be tested for use in the manufacture of organic solar cells (OSC) and organic light emitting diodes (OLED). The first order hyperpolarisabilities of these PEDOT hybrid compounds are much higher than those of the reference compound for NLO applications, namely para-nitroaniline (p-NA), which opens up a new field of application of PEDOT in NLO devices. The thermodynamic parameters such as the zero point vibrational energy (ZPVE), the enthalpy (H), the heat capacity at constant volume (Cv), the entropy (S) and the free energy (G) have been calculated and reported herein.

scholarly journals Synthesis, spectral, crystallographic, and computational investigation of a novel molecular hybrid 3-(1-((benzoyloxy)imino)ethyl)-2H-chromen-2-ones

2021 ◽  
Vol 12 (2) ◽  
pp. 133-146
Author(s):  
Kannan Gokula Krishnan ◽  
Venugopal Thanikachalam
Keyword(s):  
Density Functional ◽  
Vibrational Energy ◽  
Chemical Shifts ◽  
Normal Modes ◽  
Analytical Techniques ◽  
Zero Point ◽  
Dft Method ◽  
Structural Features ◽  
Basis Set ◽  
Monoclinic Space Group

Synthesis of 3-(1-((benzoyloxy)imino)ethyl)-2H-chromen-2-ones (1-5) was accomplished and it was characterized experimentally using various analytical techniques. Computational studies have been carried out for all compounds 1-5 using B3LYP method with 6-311++G(d,p) basis set. The optimized structural features viz. bond lengths, bond angles, and dihedral angles are compared with their single-crystal X-ray diffraction results of compound 1 (Crystal data for C18H13NO4 (M = 307.29 g/mol): Monoclinic, space group P21/c (no. 14), a = 11.399(5) Å, b = 5.876(5) Å, c = 21.859(5) Å, β = 91.060(5)°, V = 1463.9(14) Å3, Z = 4, T = 293(2) K, μ(MoKα) = 0.100 mm-1, Dcalc = 1.394 g/cm3, 13555 reflections measured (3.58° ≤ 2Θ ≤ 56.98°), 3669 unique (Rint = 0.0235) which were used in all calculations. The final R1 was 0.0444 (>2sigma(I)) and wR2 was 0.1506 (all data)), which are in good conformity with each other. Normal modes of vibrational frequencies of compounds 1-5 acquired from density-functional theory (DFT) method coincided with the experimental ones. The 1H and 13C chemical shifts of compounds 1-5 have been calculated by GIAO method and the results have been compared with the experimental ones. The first-order hyperpolarizability and their related properties of the novel molecules 1-5 are calculated computationally. The other parameters like natural bond orbital, zero-point vibrational energy, EHOMO, ELUMO, heat capacity and entropy have also been discussed.

scholarly journals Synthesis, Spectroscopic Investigation and Computational Studies of 2-Formyl-4-(Phenyldiazenyl)Phenyl Methyl Carbonate and 4-((4-Chlorophenyl)Diazenyl)-2-Formylphenyl Methyl Carbonate

2016 ◽  
Vol 66 ◽  
pp. 38-70 ◽  
Author(s):  
A. Arokiasamy ◽  
G. Manikandan ◽  
V. Thanikachalam ◽  
K. Gokula Krishnan
Keyword(s):  
Total Energy ◽  
Density Functional ◽  
Vibrational Energy ◽  
Zero Point ◽  
Basis Set ◽  
Stable Configuration ◽  
Vibrational Assignments ◽  
Computational Optimization ◽  
Methyl Carbonate ◽  
Surface Scan

Two new compounds namely 2-formyl-4-(phenyldiazenyl)phenyl methyl carbonate (FPMC) and 4-((4-chlorophenyl) diazenyl)-2-formylphenyl methyl carbonate (CFPMC) have been synthesized and have characterized using FT-IR, FT-Raman,1H and13C NMR techniques. Computational optimization studies have been carried out using Hatree–Fock (HF) and Density Functional Theory (DFT–B3LYP) methods with 6–31+G(d, p) basis set ofGaussian 09Wsoftware. The stable configuration of the title compounds were achieved theoretically by potential energy surface scan analysis. The complete vibrational assignments were performed on the basis of total energy distribution (TED) and natural bonding orbital (NBO) have been studied. Various parameters such as EHOMO, ELUMO,total energy, dipole moment, polarizability, first order hyperpolarizability, zero–point vibrational energy as well as thermal properties were analyzed and reported for the title compounds.

scholarly journals Ultrasound Assisted Synthesis, Molecular Structure,UV-Visible Assignments, MEP and Mulliken Charges Study of (E)-3-(4-chlorophenyl)-1-(4-methoxyphenyl) prop-2-en-1-one: Experimental and DFT Correlational

2021 ◽  
Vol 18 (1) ◽  
pp. 86-96
Author(s):  
Rohit S. Shinde
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Density Functional Theory Method ◽  
Atomic Charge ◽  
Dft Method ◽  
Basis Set ◽  
Geometrical Parameters ◽  
Functional Theory ◽  
Vibrational Assignments ◽  
Uv Visible

Present investigation deals with the synthesis and density functional theory study (DFT) of a chalcone derivative; (E)-3-(4-chlorophenyl)-1-(4-methoxyphenyl)prop-2-en-1-one (CPMPP). The synthesis of a CPMPP has been carried out by the reaction of 4-methoxyacetophenone and 4-chlorobenzalehyde in ethanol at 30 ℃ under ultrasound irradiation. The structure of a synthesized chalcone is affirmed on the basis of FT-IT, 1H NMR and 13C NMR. The geometry of a CPMPP is optimized by using the density functional theory method at the B3LYP/6-31G(d,p) basis set. The optimized geometrical parameters like bond length and bond angles have been computed. The absorption energies, oscillator strength, and electronic transitions have been derived at the TD-DFT method at the B3LYP/6-31G(d,p) level of theory for B3LYP/6-31G(d p) optimized geometries. The effect of polarity on the absorption energies is discussed by computing UV-visible results in dichloromethane (DCM). Since theoretically obtained wavenumbers are typically higher than experimental wavenumbers, computed wavenumbers were scaled with a scaling factor, and vibrational assignments were made by comparing experimental wavenumbers to scaled theoretical wavenumbers. Quantum chemical parameters have been determined and examined. Molecular electrostatic potential (MEP) surface plot analysis has been carried out at the same level of theory. Mulliken atomic charge study is also discussed in the present study.

scholarly journals Quantum Mechanical Investigations into Thermochemistry Properties and Electronic, Structural of Nanocrystals

2019 ◽  
Vol 29 (3) ◽  
pp. 133
Author(s):  
Huda M. Jawad
Keyword(s):  
Density Functional ◽  
Gallium Phosphide ◽  
Zero Point ◽  
Basis Set ◽  
Quantum Mechanical ◽  
Generalized Gradient ◽  
Actual System ◽  
Functional Theory ◽  
Point Energy ◽  
The Density Functional Theory

This paper presents quantum mechanical investigations that is into electronic and thermochemistry properties of Gallium phosphide. It also investigates diamondoids and nanocrystals using the density functional theory. This is done at the generalized gradient approximation of Perdew et al basis set. This has been used to create Gaussian 09 program auxiliary by Gaussian view. In order to full investigate the ionization potential, affinity, valance bond, conduction bond, zero point energy and thermochemistry properties. The result GaP diamondoids. Electron affinity and conduction band, decreases as a function of the total number of Ga and P atoms in most of the investigated range. Ionization energies zero point and valance bands increased with the number of Ga and P atoms but there are fluctuations in tetramantane and hexamantane In fact, since the present diamondoids are built from nearly cubic cages. Thermochemistry entails calculation of frequency which also includes thermochemical analysis of actual system comprising of thermal energy correction, heat capacity and entropy.

Spectroscopic investigation, HOMO–LUMO energies, natural bond orbital (NBO) analysis and thermodynamic properties of two-armed macroinitiator containing coumarin with DFT quantum chemical calculations

2016 ◽  
Vol 94 (6) ◽  
pp. 583-593 ◽  
Author(s):  
Feride Akman
Keyword(s):  
Density Functional Theory ◽  
Molecular Orbital ◽  
Electrostatic Potential ◽  
Density Functional ◽  
Natural Bond Orbital ◽  
Dft Method ◽  
Basis Set ◽  
Orbital Method ◽  
Functional Theory ◽  
Homo Lumo

In the present work, two-armed macroinitiator containing coumarin were synthesized, characterized by Fourier transform infrared spectroscopy and 1H nuclear magnetic resonance techniques and investigated theoretically using density functional theory (DFT) calculations. The molecular geometry, fundamental vibrational frequencies, atomic charges obtained from atomic polar tensors and Mulliken were analyzed by means of structure optimizations based on the DFT method with 6-31G+(d, p) as a basis set. The 1H chemical shifts were calculated by the gauge-including atomic orbital method and compared with available experimental data. The electronic properties, such as highest occupied molecular orbital – lowest unoccupied molecular orbital (HOMO–LUMO) energies, electron affinity, electronegativity, ionization energy, hardness, chemical potential, global softness, and global electrophilicity were calculated by using the DFT method. The electrostatic potential and molecular electrostatic potential surfaces were performed to predict the reactive sites of the two-armed macroinitiator. The energy difference between acceptor and donor and stabilization energy were determined using natural bond orbital analysis. The results show that the occurrence of intramolecular charge transfers within the polymer. Time-dependent density functional theory calculations of visible spectra were analyzed at different solvents. Finally, thermodynamic functions, such as enthalpy, heat capacity, and entropy, of the two-armed macroinitiator at different temperatures were calculated and the relationship with temperature was investigated.

scholarly journals Molecular Structures and Spectral Properties of Natural Indigo and Indirubin: Experimental and DFT Studies

Molecules ◽  
2019 ◽  
Vol 24 (21) ◽  
pp. 3831 ◽  
Author(s):  
Zixin Ju ◽  
Jie Sun ◽  
Yanping Liu
Keyword(s):  
Density Functional Theory ◽  
Spectral Properties ◽  
Density Functional ◽  
Dft Method ◽  
Molecular Structures ◽  
Basis Set ◽  
Frontier Molecular Orbital ◽  
Visible Absorption ◽  
Functional Theory ◽  
Uv Visible

This paper presents a comparative study on natural indigo and indirubin in terms of molecular structures and spectral properties by using both computational and experimental methods. The spectral properties were analyzed with Fourier transform infrared (FTIR), Raman, UV-Visible, and fluorescence techniques. The density functional theory (DFT) method with B3LYP using 6-311G(d,p) basis set was utilized to obtain their optimized geometric structures and calculate the molecular electrostatic potential, frontier molecular orbitals, FTIR, and Raman spectra. The single-excitation configuration interaction (CIS), time-dependent density functional theory (TD-DFT), and polarization continuum model (PCM) were used to optimize the excited state structure and calculate the UV-Visible absorption and fluorescence spectra of the two molecules at B3LYP/6-311G(d,p) level. The results showed that all computational spectra agreed well with the experimental results. It was found that the same vibrational mode presents a lower frequency in indigo than that in indirubin. The frontier molecular orbital analysis demonstrated that the UV-Visible absorption and fluorescence bands of indigo and indirubin are mainly derived from π → π* transition. The results also implied that the indigo molecule is more conjugated and planar than indirubin, thereby exhibiting a longer maximum absorption wavelength and stronger fluorescence peak.

Density Functional Theory Study of Intermolecular Interaction between RDX and H2O

2013 ◽  
Vol 750-752 ◽  
pp. 1848-1851
Author(s):  
Xiu Lin Zeng ◽  
Xue Hai Ju
Keyword(s):  
Density Functional ◽  
Natural Bond Orbital ◽  
Density Functional Method ◽  
Zero Point ◽  
Functional Method ◽  
Binding Energies ◽  
Basis Set ◽  
Free Energies ◽  
Functional Theory ◽  
Dimerization Process

The density functional method of wB97xD in combination of 6-31+G** basis set was applied to the study of the heterodimers between hexahydro-1,3,5-trinitro-1,3,5-triazine and water. Three stable dimers were located. The binding energies have been corrected for the zero-point vibrational and basis set superposition errors. The largest corrected binding energy is 26.21 kJ/mol. Natural bond orbital analyses and frequency calculations were performed on each optimized structure. The thermodynamic properties of enthalpies, entropies and Gibbs free energies in the dimerization process were presented.

Molecular Structure, Vibrational Spectroscopy and Homo, Lumo Studies of 4-methyl-N-(2-methylphenyl) Benzene Sulfonamide Using DFT Method

2013 ◽  
Vol 665 ◽  
pp. 101-111 ◽  
Author(s):  
K. Sarojini ◽  
H. Krishnan ◽  
Charles C. Kanagam ◽  
S. Muthu
Keyword(s):  
Density Functional ◽  
Molecular Electrostatic Potential ◽  
Structural Parameters ◽  
Dft Method ◽  
Basis Set ◽  
X Ray Diffraction ◽  
Functional Theory ◽  
Homo And Lumo ◽  
Homo Lumo ◽  
Sulfonamide Compound

The sulfonamide compound, 4-methyl-N-(2-methylphenyl) benzene sulfonamide has been synthesized and characterized by FTIR, NMR, UV-Vis, single crystal X-ray diffraction and thermal analysis. Density functional (DFT) calculations have been carried out for the title compound by performing DFT level of theory using B3LYP/6-31G (d,p) basis set. The calculated results show that the predicted geometry can well reproduce the structural parameters. Predicted vibrational frequencies have been assigned and compared with the experimental IR spectra and they support each other. In addition, atomic charges, frontier molecular orbitals and molecular electrostatic potential were carried out by using density functional theory (DFT/B3LYP) 6-31G (d, p) basis set. The calculated Homo and Lumo energies show that charge transfer occur in the molecule.

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