scholarly journals Exchange-correlation kernels for excited states in solids

2001 ◽  
Vol 63 (23) ◽  
Author(s):  
Krzysztof Tatarczyk ◽  
Arno Schindlmayr ◽  
Matthias Scheffler
Keyword(s):  
Excited States ◽  
Exchange Correlation ◽  
Correlation Kernels

Assessing Accuracy of Exchange-Correlation Functionals for the Description of Atomic Excited States

2016 ◽  
Vol 230 (9) ◽  
Author(s):  
Marcin Makowski ◽  
Martyna Hanas
Keyword(s):  
Excited States ◽  
Density Functional ◽  
Adiabatic Approximation ◽  
Good Accuracy ◽  
Functional Theory ◽  
Exchange Correlation ◽  
Correlation Kernels ◽  
Atomic Excitations

AbstractThe performance of exchange-correlation functionals for the description of atomic excitations is investigated. A benchmark set of excited states is constructed and experimental data is compared to Time-Dependent Density Functional Theory (TDDFT) calculations. The benchmark results show that for the selected group of functionals good accuracy may be achieved and the quality of predictions provided is competitive to computationally more demanding coupled-cluster approaches. Apart from testing the standard TDDFT approaches, also the role of self-interaction error plaguing DFT calculations and the adiabatic approximation to the exchange-correlation kernels is given some insight.

scholarly journals Excited States Calculations of MoS2@ZnO and WS2@ZnO Two-Dimensional Nanocomposites for Water-Splitting Applications

Energies ◽  
2021 ◽  
Vol 15 (1) ◽  
pp. 150
Author(s):  
Yin-Pai Lin ◽  
Boris Polyakov ◽  
Edgars Butanovs ◽  
Aleksandr A. Popov ◽  
Maksim Sokolov ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Optical Properties ◽  
Water Splitting ◽  
Excited States ◽  
Density Functional ◽  
Visible Region ◽  
Transition Metal Dichalcogenide ◽  
Two Dimensional ◽  
Functional Theory ◽  
Exchange Correlation

Transition metal dichalcogenide (TMD) MoS2 and WS2 monolayers (MLs) deposited atop of crystalline zinc oxide (ZnO) and graphene-like ZnO (g-ZnO) substrates have been investigated by means of density functional theory (DFT) using PBE and GLLBSC exchange-correlation functionals. In this work, the electronic structure and optical properties of studied hybrid nanomaterials are described in view of the influence of ZnO substrates thickness on the MoS2@ZnO and WS2@ZnO two-dimensional (2D) nanocomposites. The thicker ZnO substrate not only triggers the decrease of the imaginary part of dielectric function relatively to more thinner g-ZnO but also results in the less accumulated charge density in the vicinity of the Mo and W atoms at the conduction band minimum. Based on the results of our calculations, we predict that MoS2 and WS2 monolayers placed at g-ZnO substrate yield essential enhancement of the photoabsorption in the visible region of solar spectra and, thus, can be used as a promising catalyst for photo-driven water splitting applications.

scholarly journals Assessing Configurational Sampling in the Quantum Mechanics/Molecular Mechanics Calculation of Temoporfin Absorption Spectrum and Triplet Density of States

Molecules ◽  
2018 ◽  
Vol 23 (11) ◽  
pp. 2932 ◽  
Author(s):  
Martina De Vetta ◽  
Omar Baig ◽  
Dorika Steen ◽  
Juan Nogueira ◽  
Leticia González
Keyword(s):  
Quantum Mechanics ◽  
Molecular Mechanics ◽  
Excited States ◽  
Experimental Spectrum ◽  
Triplet States ◽  
Absorption Properties ◽  
Exchange Correlation ◽  
Molecular Mechanics Calculation ◽  
Electrostatic Embedding ◽  
Good Agreement

The absorption properties of Temoporfin, a second-generation photosensitizer employed in photodynamic therapy, are calculated with an electrostatic-embedding quantum mechanics/molecular mechanics (QM/MM) scheme in methanol. The suitability of several ensembles of geometries generated by different sampling techniques, namely classical-molecular-dynamics (MD) and QM/MM-MD thermal sampling, Wigner quantum sampling and a hybrid protocol, which combines the thermal and quantum approaches, is assessed. It is found that a QM description of the chromophore during the sampling is needed in order to achieve a good agreement with respect to the experimental spectrum. Such a good agreement is obtained with both QM/MM-MD and Wigner samplings, demonstrating that a proper description of the anharmonic motions of the chromophore is not relevant in the computation of the absorption properties. In addition, it is also found that solvent organization is a rather fast process and a long sampling is not required. Finally, it is also demonstrated that the same exchange-correlation functional should be employed in the sampling and in the computation of the excited states properties to avoid unphysical triplet states with relative energies close or below 0 eV.

Sign in / Sign up

Export Citation Format

Share Document