On the basis set convergence of TD-DFT oscillator strengths: Dinitrophenylhydrazones as a case study

2007 ◽  
Vol 804 (1-3) ◽  
pp. 31-34 ◽  
Author(s):  
Denis Jacquemin ◽  
Eric A. Perpète
Keyword(s):  
Oscillator Strengths ◽  
Basis Set ◽  
Set Convergence ◽  
Td Dft

Study on the 4-ethoxy-2-methyl-5-(4-morpholinyl)-3(2H)-pyridazinone using FT-IR, 1H and 13C NMR, UV-vis spectroscopy, and DFT/HSEH1PBE method

2018 ◽  
Vol 96 (9) ◽  
pp. 1042-1052 ◽  
Author(s):  
Bülent Dede ◽  
Davut Avcı ◽  
Semiha Bahçeli
Keyword(s):  
Gas Phase ◽  
Electronic Absorption ◽  
Vibrational Frequencies ◽  
Oscillator Strengths ◽  
Basis Set ◽  
Spectroscopic Techniques ◽  
Vis Spectroscopy ◽  
Td Dft ◽  
Ft Ir ◽  
C Nmr

In this work, the 4-ethoxy-2-methyl-5-(4-morpholinyl)-3(2H)-pyridazinone (or emarfazone, C11H17N3O3) compound, which has many biological functions, has been investigated using FT-IR, 1H and 13C NMR (in CDCl3 solvent), and UV-vis (in ethanol solvent) spectroscopic techniques. Furthermore, the optimized molecular structure, conformational analysis, vibrational frequencies and their assignments, 1H and 13C NMR chemical shift values (in gas phase and CHCl3 solvent), HOMO–LUMO, MEP (molecular electrostatic potential), NBO (natural bond orbital) analyses, and nonlinear optical (NLO) parameters of the title compound in the ground state have been explored by using DFT/HSEH1PBE method with the 6-311++G(d,p) basis set. The electronic absorption maximum wavelengths and oscillator strengths (in gas phase and ethanol solvent) were also obtained at TD-DFT/HSEH1PBE level. A comparison among the experimental and calculated results at the mentioned level indicates that the vibrational frequencies and maximum electronic absorption wavelengths are in good agreement with each other.

scholarly journals A Theoretical Study of 5-methyl-2-isopropylphenol (Thymol) by DFT

2021 ◽  
pp. 812-830
Author(s):  
Raksha Gupta
Keyword(s):  
Population Analysis ◽  
Dft Method ◽  
Geometric Optimization ◽  
Oscillator Strengths ◽  
Basis Set ◽  
Excitation Energies ◽  
Mulliken Population ◽  
Visible Absorption ◽  
Vertical Excitation ◽  
Td Dft

Gaussian 09, RevisionA.01, software package was used for the theoretical quantum chemical calculations of 5-methyl-2-isopropylphenol. DFT/B3LYP/6-311G (d, p) basis was used to perform geometric optimization and vibrational frequency determination of the molecule. The statistical thermochemical calculations of the molecule were done at DFT/B3LYP/6-311G (d, p) basis set to calculate the standard thermodynamic functions: heat capacity (CV), entropy (S) and Enthalpy (E). Various NLO properties like total dipole moment (µ), mean linear polarizability (α), anisotropic polarizability (Δα), first order polarizability (β), and second order hyperpolarizability (γ) in terms of x, y, z components were calculated at DFT/B3LYP/6-311G (d, p) basis set for 5-methyl-2-isopropylphenol. Mulliken population analysis was also done using the same basis set. Time Dependent DFT (TD-DFT) method using the same basis set was used to compute UV-Visible absorption spectra, ECD spectra, electronic transitions, vertical excitation energies and oscillator strengths of 5-methyl-2-isopropylphenol.FMO analysis, ESP study were also done using the same basis set.

The optoelectronic properties of π-conjugated organic molecules based on terphenyl and pyrrole for BHJ solar cells: DFT / TD-DFT theoretical study

2021 ◽  
Vol 10 (4) ◽  
pp. 489-502 ◽  
Author(s):  
M. Raftani ◽  
T. Abram ◽  
W. Loued ◽  
R. Kacimi ◽  
A. Azaid ◽  
...  
Keyword(s):  
Solar Cells ◽  
Quantum Chemical ◽  
Chemical Method ◽  
Chemical Reactivity ◽  
Optoelectronic Properties ◽  
Oscillator Strengths ◽  
Frontier Molecular Orbital ◽  
Bandgap Energy ◽  
Quantum Chemical Method ◽  
Td Dft

In the present paper, four π-conjugated materials, based on terphenyl and pyrrole, with A–D–A structure have been theoretically studied to propose new organic compounds to be used in the organic solar cell field. Moreover, the geometrical and optoelectronic properties of the designed molecules M1, M2, M3 and M4 have been computed after optimization in their fundamental states, using the quantum chemical method DFT / B3LYP/ 6−311G (d, p). Different parameters including HOMO and LUMO energy levels, bandgap energy, frontier molecular orbital (FMO), chemical reactivity indices, the density of states (DOS), Voc, electrostatic potential (ESP), and thermodynamic parameters at several temperatures in the range of 0-500 K have been determined. The absorption properties including the transition energy, the wavelengths (λmax), the excitation vertical energy, and the corresponding oscillator strengths of these molecules have been studied using the quantum chemical method TD−DFT / CAM–B3LYP / 6–311G (d, p). The obtained results of our studied compounds show that M3 (with 2H, 2'H-1, 1'-biisoindole moiety) as a donor group has special optoelectronic, absorption, and good photovoltaic characteristics. Thus, they can be utilized as an electron-donating in organic solar cells BHJ type.

Excitation Spectra in the Time-Dependent Density-Functional Theory with Gradient Correction

1999 ◽  
Vol 579 ◽  
Author(s):  
Naoto Uimezawa ◽  
Susumu Saito
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Local Density ◽  
Oscillator Strengths ◽  
Time Dependent ◽  
Basis Set ◽  
Excitation Spectra ◽  
Functional Theory ◽  
Gradient Correction ◽  
Dependent Density

ABSTRACTWe study tile optical absorption spectra of Na clusters using the time-dependent density-functional theory with gradient correction. A jellium-sphere background model, which is free from basis-set incompleteness error and is suitable for the comparison of various theoretical methods, is adopted. For energies of surface-plasinon excitations governing profiles of photoabsorption spectra with huge oscillator strengths., the gradient correction by van Leeiiwen and Baerends with correct asymptotic behavior of the effective potential is found to show considerable improvement over the time-dependent local-density approximation.

TD-DFT calculations of the excited states of metalloporphyrins relevant to organic solar photovoltaic cells

2014 ◽  
Vol 18 (06) ◽  
pp. 475-492 ◽  
Author(s):  
Neha Agnihotri ◽  
Ronald P. Steer
Keyword(s):  
Dft Calculations ◽  
Electronic State ◽  
Excited States ◽  
Photovoltaic Cells ◽  
Oscillator Strengths ◽  
Solar Photovoltaic ◽  
Dft Methods ◽  
Radiative Transitions ◽  
Td Dft ◽  
Triplet Excited States

The molecular orbital energies and symmetries, electronic state energies and symmetries, and orbital compositions and oscillator strengths for one-photon radiative transitions up to an energy of 4 eV have been calculated by DFT and TD-DFT methods for 15 d0 and d10 metalloporphyrins. Data for both singlet and triplet excited states are reported and used to identify potential candidates for use as photon upconverters by homomolecular triplet–triplet annihilation.

Ab initio predictions of the zero field splittings and the singlet–triplet transition strengths for the n → π* transition of selenoformaldehyde

1993 ◽  
Vol 71 (10) ◽  
pp. 1706-1712 ◽  
Author(s):  
D.C. Moule ◽  
L. Chantranupong ◽  
R.H. Judge ◽  
D.J. Clouthier
Keyword(s):  
Energy Levels ◽  
Random Phase ◽  
Open Shell ◽  
Oscillator Strengths ◽  
Basis Set ◽  
Zero Field ◽  
Zero Field Splitting ◽  
Hartree Fock ◽  
Lower Valence ◽  
Polarization Functions

The energy levels of the lower valence and Rydberg states of selenoformaldehyde, CH2Se, have been calculated by the SCF/CI method. Wavefunctions for the ROHF (restricted open shell Hartree–Fock) states were obtained with the Binnings–Curtis double-ζ basis set, augmented with Rydberg and polarization functions. Configuration interaction was applied to the parent configurations, PCMO (parent configuration molecular orbital). Oscillator strengths were evaluated for the allowed electric dipole transitions by the RPA (random phase approximation), and SOPPA (second-order polarization propagator approximation) methods. The spin-orbit contribution to the zero field splitting of the first triplet state, 3A2(n,π*) as well as the oscillator strengths to the three spin components were calculated by perturbation theory. These calculations predict that the Sx, Sy, and Sz components are shifted by −96.091,−96.707, and + 29.167 cm−1, respectively, from their unperturbed position. The oscillator strengths for the three components fx, fy, and fz of the 3A2(n,π*) ← 1A1(g.s.) transition were calculated to be 3.45 × 10−7, 1.15 × 10−7, and 173.0 × 10−7.

Donor Functionalized Perylene and Different π-Spacers Based Sensitizers for DSSC Applications - A Theoretical Approach

2021 ◽  
Author(s):  
D. Nicksonsebastin ◽  
P. Pounraj ◽  
Prasath M
Keyword(s):  
Density Functional Theory ◽  
Solar Cell ◽  
Gas Phase ◽  
Density Functional ◽  
Basis Set ◽  
Dye Sensitized Solar Cell ◽  
Functional Theory ◽  
Dye Sensitized ◽  
Td Dft ◽  
Organic Sensitizers

Abstract Perylene based novel organic sensitizers for the Dye sensitized solar cell applications are investigated by using Density functional theory (DFT) and time dependant density functional theory (TD-DFT).The designed sensitizers have perylene and dimethylamine (DM) and N-N-dimethylaniline(DMA) functionalized perylene for the dssc applications.π-spacers are thiophene andcyanovinyl groups and cyanoacrylic acid is chosen as the acceptor for the designed sensitizers. The studied sensitizers were fully optimized by density functional theory at B3LYP/6-311G basis set on gas phase and DMF phase. The electronic absorption of the sensitizers is analyzed by TD-DFT at B3LYP/6-311G basis set in both gas and DMF phase.

scholarly journals 1,3-Di(hetero)aryl-7-substituted Pyrenes—An Undiscovered Area of Important Pyrene Derivatives

Proceedings ◽  
2019 ◽  
Vol 41 (1) ◽  
pp. 28
Author(s):  
Dawid Zych
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Theoretical Calculations ◽  
Basis Set ◽  
Functional Theory ◽  
Td Dft ◽  
Pyrene Derivatives ◽  
Osmium Complexes ◽  
The Subject ◽  
Theoretical Considerations

In this work, the necessity of synthesis of 1,3-di(hetero)aryl-7-substituted pyrenes is presented based on the results of theoretical calculations by using density functional theory (DFT) and time-dependent density functional theory (TD-DFT) by using Gaussian 09 program with B3LYP exchange-correlation functional and 6-31G** basis set. What is more, the synthetic routes with feasible reagents and conditions are presented. The subject of theoretical considerations are two pyrene derivatives which contain at position 1 and 3 pyrazolyl substituents and at position 7 amine (1) or boron (2) derivative. The theoretical calculations were also performed for the osmium complexes with mentioned ligands (3 and 4). The influence of electron-donating/accepting character of the substituent at position 7 of pyrene on the properties of molecules has been established.

Basis set convergence of atomic axial tensors obtained from self‐consistent field calculations using London atomic orbitals

1994 ◽  
Vol 100 (9) ◽  
pp. 6620-6627 ◽  
Author(s):  
Keld L. Bak ◽  
Poul Jo/rgensen ◽  
Trygve Helgaker ◽  
Kenneth Ruud ◽  
Hans Jo/rgen Aa. Jensen
Keyword(s):  
Basis Set ◽  
Set Convergence ◽  
Atomic Orbitals ◽  
Consistent Field ◽  
Self Consistent ◽  
Self Consistent Field
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