Determination of vibrational energy levels and transition dipole moments of CO2 molecules by density functional theory

2008 ◽  
Vol 252 (2) ◽  
pp. 108-114 ◽  
Author(s):  
Zhi Liang ◽  
Hai-Lung Tsai
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Vibrational Energy ◽  
Dipole Moments ◽  
Energy Levels ◽  
Transition Dipole ◽  
Functional Theory ◽  
Transition Dipole Moments ◽  
Vibrational Energy Levels

Ab Initio Calculations of Vibrational Energy Levels and Transition Dipole Moments of CO2 Molecules

2008 ◽  
Author(s):  
Zhi Liang ◽  
Hai-Lung Tsai
Keyword(s):  
Ab Initio ◽  
Vibrational Energy ◽  
Molecular Spectroscopy ◽  
Dipole Moments ◽  
Energy Levels ◽  
Wave Functions ◽  
Molecular Vibration ◽  
Transition Dipole ◽  
Transition Dipole Moments ◽  
Vibrational Energy Levels

Ab initio MD simulation of laser-matter interactions is a hot area in the study of the mechanisms of photo-dissociation, photo-ionization and laser induced chemical reactions. The major problems in the study of laser-molecule interactions are to determine the energies and wave functions of molecular vibration states and the molecular transition dipole moments. An efficient method is presented to calculate the intramolecular potential energies and electrical dipole moments of CO2 molecules at the electronic ground state by solving the Kohn-Sham (KS) equation for a total of 101,992 nuclear configurations. The Projector-Augmented Wave (PAW) exchange-correlation potential functionals and Plane Wave (PW) basis functions were used in solving the KS equation. The calculated intra-molecular potential function was then included in the pure vibrational Schro¨dinger equation to determine the vibrational energy eigen values and eigen functions. The vibrational wave functions combined with the calculated dipole moment function were used to determine the transition dipole moments. The calculated results have a good agreement with experimental values. These results can be further used to determinations of molecular spectroscopy and laser absorption coefficients.

scholarly journals Substituent Effects on the Solubility and Electronic Properties of the Cyanine Dye Cy5: Density Functional and Time-Dependent Density Functional Theory Calculations

Molecules ◽  
2021 ◽  
Vol 26 (3) ◽  
pp. 524
Author(s):  
Austin Biaggne ◽  
William B. Knowlton ◽  
Bernard Yurke ◽  
Jeunghoon Lee ◽  
Lan Li
Keyword(s):  
Density Functional Theory ◽  
Dipole Moment ◽  
Density Functional ◽  
Dipole Moments ◽  
Time Dependent ◽  
Cyanine Dye ◽  
Transition Dipole ◽  
Functional Theory ◽  
Solvation Energies ◽  
Transition Dipole Moments

The aggregation ability and exciton dynamics of dyes are largely affected by properties of the dye monomers. To facilitate aggregation and improve excitonic function, dyes can be engineered with substituents to exhibit optimal key properties, such as hydrophobicity, static dipole moment differences, and transition dipole moments. To determine how electron donating (D) and electron withdrawing (W) substituents impact the solvation, static dipole moments, and transition dipole moments of the pentamethine indocyanine dye Cy5, density functional theory (DFT) and time-dependent (TD-) DFT calculations were performed. The inclusion of substituents had large effects on the solvation energy of Cy5, with pairs of withdrawing substituents (W-W pairs) exhibiting the most negative solvation energies, suggesting dyes with W-W pairs are more soluble than others. With respect to pristine Cy5, the transition dipole moment was relatively unaffected upon substitution while numerous W-W pairs and pairs of donating and withdrawing substituents (D-W pairs) enhanced the static dipole difference. The increase in static dipole difference was correlated with an increase in the magnitude of the sum of the Hammett constants of the substituents on the dye. The results of this study provide insight into how specific substituents affect Cy5 monomers and which pairs can be used to engineer dyes with desired properties.

scholarly journals Metastable One-Electron Excited States of Charged Fullerenes

2019 ◽  
Vol 2019 ◽  
pp. 1-4
Author(s):  
Rafael V. Arutyunyan ◽  
Alexander D. Vasiliev ◽  
Yuri N. Obukhov ◽  
Alexander V. Osadchy
Keyword(s):  
Density Functional ◽  
Dipole Moments ◽  
Three Dimensional ◽  
Density Functional Theory Method ◽  
Transition Dipole ◽  
Functional Theory ◽  
The Density Functional Theory ◽  
Transition Dipole Moments ◽  
Quantum Transitions ◽  
Wavelength Radiation

We study the spontaneous emission processes for the quantum transitions between electron states of a charged C60 fullerene. Lifetimes for the transitions between the volume-localized electron levels and the surface-localized electron levels are evaluated and compared with the transitions between two surface-localized electron levels. We find the lifetimes by computing the transition dipole moments on the basis of the numeric calculations of the three-dimensional electron wave functions of a charged fullerene by making use of the density functional theory method implemented in the QuantumEspresso package. We show that the lifetime of a volume-localized level is of order of 1 μs for a transition energy of about 5 eV. This suggests to consider the possibility of using charged fullerenes for generating short-wavelength radiation, including coherent radiation in this range.

Theoretical determination of the structures of CaSiO3 perovskites

2006 ◽  
Vol 62 (6) ◽  
pp. 1025-1030 ◽  
Author(s):  
Razvan Caracas ◽  
Renata M. Wentzcovitch
Keyword(s):  
Crystal Structure ◽  
Experimental Data ◽  
Density Functional Theory ◽  
Density Functional ◽  
Theoretical Determination ◽  
Functional Theory ◽  
Starting Point ◽  
Atomic Coordinates ◽  
The Ideal

Density functional theory is used to determine the possible crystal structure of the CaSiO3 perovskites and their evolution under pressure. The ideal cubic perovskite is considered as a starting point for studying several possible lower-symmetry distorted structures. The theoretical lattice parameters and the atomic coordinates for all the structures are determined, and the results are discussed with respect to experimental data.

scholarly journals Taguchi-Assisted Optimization Technique and Density Functional Theory for Green Synthesis of a Novel Cu-MOF Derived From Caffeic Acid and Its Anticancerious Activities

2021 ◽  
Vol 9 ◽  
Author(s):  
Malihe Zeraati ◽  
Ali Mohammadi ◽  
Somayeh Vafaei ◽  
Narendra Pal Singh Chauhan ◽  
Ghasem Sargazi
Keyword(s):  
Density Functional Theory ◽  
Caffeic Acid ◽  
Density Functional ◽  
Energy Levels ◽  
Optimization Technique ◽  
Nitrogen Adsorption ◽  
High Porosity ◽  
Anticancer Activities ◽  
Functional Theory ◽  
Sem Analyses

In this paper, we have reported an innovative greener method for developing copper-metal organic frameworks (Cu-MOFs) using caffeic acid (CA) as a linker extracted from Satureja hortensis using ultrasonic bath. The density functional theory is used to discuss the Cu-MOF-binding reaction mechanism. In order to achieve a discrepancy between the energy levels of the interactive precursor orbitals, the molecules have been optimized using the B3LYP/6–31G method. The Taguchi method was used to optimize the key parameters for the synthesis of Cu-MOF. FT-IR, XRD, nitrogen adsorption, and SEM analyses are used to characterize it. The adsorption/desorption and SEM analyses suggested that Cu-MOF has a larger surface area of 284.94 m2/g with high porosity. Cu-MOF has shown anticancer activities against the human breast cancer (MDA-MB-468) cell lines, and it could be a potent candidate for clinical applications.

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