Geometrical Correction for the Inter- and Intramolecular Basis Set Superposition Error in Periodic Density Functional Theory Calculations

Weak interactions between organic donor and acceptor molecules resulting in cofacially-stacked aggregates ("CT complexes") were studied by second-order many-body perturbation theory (MP2) and by gradient-corrected hybrid Hartree-Fock/density functional theory (B3LYP exchange-correlation functional). The complexes consist of tetrathiafulvalene (TTF) and related compounds and tetracyanoethylene (TCNE). Density functional theory (DFT) and MP2 molecular equilibrium geometries of the component structures are calculated by means of 6-31G*, 6-31G*(0.25), 6-31++G**, 6-31++G(3df,2p) and 6-311G** basis sets. Reliable molecular geometries are obtained for the donor and acceptor compounds considered. The geometries of the compounds were kept frozen in optimizing aggregate structures with respect to the intermolecular distance. The basis set superposition error (BSSE) was considered (counterpoise correction). According to the DFT and MP2 calculations laterally-displaced stacks are more stable than vertical stacks. The charge transfer from the donor to the acceptor is small in the ground state of the isolated complexes. The cp-corrected binding energies of TTF/TCNE amount to -1.7 and -6.3 kcal/mol at the DFT(B3LYP) and MP2(frozen) level of theory, respectively (6-31G* basis set). Larger binding energies were obtained by Hobza's 6-31G*(0.25) basis set. The larger MP2 binding energies suggest that the dispersion energy is underestimated or not considered by the B3LYP functional. The energy increases when S in TTF/TCNE is replaced by O or NH but decreases with substitution by Se. The charge-transferred complexes in the triplet state are favored in the vertical arrangement. Self-consistent-reaction-field (SCRF) calculations predicted a gain in binding energy with solvation for the ground-state complex. The ground-state charge transfer between the components is increased up to 0.8 e in polar solvents.

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Analysis of vibratinal spectra of 8-hydroxyquinoline and its 5,7-dichloro, 5,7-dibromo, 5,7-diiodo and 5,7-dinitro derivatives based on density functional theory calculations

Open Chemistry ◽

10.2478/s11532-006-0061-x ◽

2007 ◽

Vol 5 (1) ◽

pp. 201-220 ◽

Cited By ~ 12

Author(s):

Khaled Bahgat ◽

Abdel Ragheb

Keyword(s):

Density Functional Theory ◽

Dft Calculations ◽

Density Functional ◽

Density Functional Theory Calculations ◽

Basis Set ◽

Normal Coordinate ◽

Functional Theory ◽

The Density Functional Theory ◽

Vibrational Bands ◽

Good Agreement

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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