Basis set dependence of NMR spin–spin couplings in density functional theory calculations: first row and hydrogen atoms

AbstractThe geometry, frequency and intensity of the vibrational bands of 8-hydroxyquinoline and its 5,7-dichloro, 5,7-dibromo, 5,7-diiodo and 5,7-dinitro derivatives were obtained by the density functional theory (DFT) calculations with Becke3-Lee-Parr (B3LYP) functional and 6-31G* basis set. The effects of chloride, bromide, iodide and nitro substituent on the vibrational frequencies of 8-hydroxyquinoline have been investigated. The assignments have been proposed with aid of the results of normal coordinate analysis. The observed and calculated spectra are found to be in good agreement.

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Basis set dependence of phosphate frequencies in density functional theory calculations

International Journal of Quantum Chemistry ◽

10.1002/qua.23182 ◽

2011 ◽

Vol 112 (11) ◽

pp. 2435-2439 ◽

Cited By ~ 5

Author(s):

Maria Rudbeck

Keyword(s):

Density Functional Theory ◽

Density Functional ◽

Density Functional Theory Calculations ◽

Basis Set ◽

Functional Theory

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Quantum chemical studies on the molecular structure, spectroscopic and electronic properties of (6-Methoxy-2-oxo-2H-chromen-4-yl)-methyl pyrrolidine-1-carbodithioate

Materials Science-Poland ◽

10.1515/msp-2016-0115 ◽

2016 ◽

Vol 34 (4) ◽

pp. 886-904 ◽

Cited By ~ 5

Author(s):

Meryem Evecen ◽

Hasan Tanak

Keyword(s):

Density Functional Theory ◽

Density Functional ◽

Electronic Absorption Spectra ◽

Chemical Shifts ◽

Density Functional Theory Calculations ◽

Molecular Geometry ◽

Basis Set ◽

Functional Theory ◽

Hartree Fock ◽

Chemical Studies

AbstractIn this paper, the molecular geometry, vibrational frequencies and chemical shifts of (6-Methoxy-2-oxo-2H-chromen-4-yl)methyl pyrrolidine-1-carbodithioate in the ground state have been calculated using the Hartree-Fock and density functional methods with the 6-311++G(d,p) basis set. To investigate the nonlinear optical properties of the title compound, the polarizability and the first hyperpolarizability were calculated. The conformational properties of the molecule have been determined by analyzing molecular energy properties. Using the time dependent density functional theory, electronic absorption spectra have been calculated. Frontier molecular orbitals, natural bond orbitals, natural atomic charges and thermodynamical parameters were also investigated by using the density functional theory calculations.

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Defective BN Nanotubes: A Density Functional Theory Study of B-11 and N-14 NQR Parameters

Zeitschrift für Naturforschung A ◽

10.1515/zna-2009-3-413 ◽

2009 ◽

Vol 64 (3-4) ◽

pp. 251-256 ◽

Cited By ~ 8

Author(s):

Masoud Giahi ◽

Mahmoud Mirzaei

Keyword(s):

Density Functional Theory ◽

Density Functional ◽

Boron Nitride Nanotubes ◽

Basis Set ◽

Structural Defects ◽

Hydrogen Atoms ◽

Functional Theory ◽

Quadrupole Resonance ◽

Nqr Parameters ◽

Structure Properties

Abstract A density functional theory (DFT) study is performed to investigate the influence of structural defects on the electronic structure properties of perfect boron nitride nanotubes (BNNTs). To this aim, as representative models, the single-walled (6,0) BNNT consisting of 36 boron, 36 nitrogen, and 12 hydrogen atoms and the single-walled (4,4) BNNT consisting of 36 boron, 36 nitrogen, and 16 hydrogen atoms are considered. The nuclear quadrupole resonance (NQR) parameters are calculated and compared in two perfect and defective models of the considered BNNTs. The results indicate that due to formation of non-hexagonal rings in the defective model because of removing a B-N bond, the NQR parameters at the sites of first neighbouring nuclei are significantly influenced by imposed perturbation, however, the sites of other nuclei, farther from perturbation, remain almost unchanged. The calculations are performed at the level of the BLYP method and 6-31G* standard basis set using the GAUSSIAN 98 package

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