scholarly journals Time-dependent density functional theory as a foundation for a firmer understanding of sum-over-states density functional perturbation theory: ?Loc.3? approximation

2002 ◽  
Vol 91 (2) ◽  
pp. 67-83 ◽  
Author(s):  
Elisa Fadda ◽  
Mark E. Casida ◽  
Dennis R. Salahub
Keyword(s):  
Density Functional Theory ◽  
Perturbation Theory ◽  
Density Functional ◽  
Time Dependent ◽  
Functional Theory ◽  
Density Functional Perturbation Theory ◽  
Dependent Density

scholarly journals Optical and Electronic Properties of Organic NIR-II Fluorophores by Time-Dependent Density Functional Theory and Many-Body Perturbation Theory: GW-BSE Approaches

Nanomaterials ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 2293
Author(s):  
Nguyet N. T. Pham ◽  
Seong Hun Han ◽  
Jong S. Park ◽  
Seung Geol Lee
Keyword(s):  
Density Functional Theory ◽  
Perturbation Theory ◽  
Electronic Properties ◽  
Density Functional ◽  
Time Dependent ◽  
Many Body ◽  
Functional Theory ◽  
Optical And Electronic Properties ◽  
Many Body Perturbation Theory ◽  
Dependent Density

Organic-molecule fluorophores with emission wavelengths in the second near-infrared window (NIR-II, 1000–1700 nm) have attracted substantial attention in the life sciences and in biomedical applications because of their excellent resolution and sensitivity. However, adequate theoretical levels to provide efficient and accurate estimations of the optical and electronic properties of organic NIR-II fluorophores are lacking. The standard approach for these calculations has been time-dependent density functional theory (TDDFT). However, the size and large excitonic energies of these compounds pose challenges with respect to computational cost and time. In this study, we used the GW approximation combined with the Bethe-Salpeter equation (GW-BSE) implemented in many-body perturbation theory approaches based on density functional theory. This method was used to perform calculations of the excited states of two NIR molecular fluorophores (BTC980 and BTC1070), going beyond TDDFT. In this study, the optical absorption spectra and frontier molecular orbitals of these compounds were compared using TDDFT and GW-BSE calculations. The GW-BSE estimates showed excellent agreement with previously reported experimental results.

Benchmark of Simplified Time-Dependent Density Functional Theory for UV-Vis Spectral Properties of Porphyrinoids

2019 ◽  
Author(s):  
Kamal Batra ◽  
Stefan Zahn ◽  
Thomas Heine
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Large Scale ◽  
Absolute Error ◽  
Time Dependent ◽  
Basis Set ◽  
Basis Sets ◽  
Functional Theory ◽  
Framework Materials ◽  
Dependent Density

<p>We thoroughly benchmark time-dependent density- functional theory for the predictive calculation of UV/Vis spectra of porphyrin derivatives. With the aim to provide an approach that is computationally feasible for large-scale applications such as biological systems or molecular framework materials, albeit performing with high accuracy for the Q-bands, we compare the results given by various computational protocols, including basis sets, density-functionals (including gradient corrected local functionals, hybrids, double hybrids and range-separated functionals), and various variants of time-dependent density-functional theory, including the simplified Tamm-Dancoff approximation. An excellent choice for these calculations is the range-separated functional CAM-B3LYP in combination with the simplified Tamm-Dancoff approximation and a basis set of double-ζ quality def2-SVP (mean absolute error [MAE] of ~0.05 eV). This is not surpassed by more expensive approaches, not even by double hybrid functionals, and solely systematic excitation energy scaling slightly improves the results (MAE ~0.04 eV). </p>

Photophysical Properties of N-Methyl and N-Acetyl Substituted Alloxazine: A Theoretical Investigation

2021 ◽  
Author(s):  
Huimin Guo ◽  
Xiaolin Ma ◽  
Zhiwen Lei ◽  
Yang Qiu ◽  
Bernhard Dick ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Electronic Structure ◽  
Theoretical Investigation ◽  
Density Functional ◽  
Photophysical Properties ◽  
Time Dependent ◽  
Functional Theory ◽  
Td Dft ◽  
Dependent Density

The electronic structure and photophysical properties of a series of N-Methyl and N-Acetyl substituted alloxazine (AZs) were investigated with extensive density functional theory (DFT) and time-dependent density functional theory (TD-DFT)...

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