Comparative DFT study for molecular geometries and spectra of methyl pheophorbides-a: test of M06-2X and two other functionals

2010 ◽  
Vol 14 (07) ◽  
pp. 592-604 ◽  
Author(s):  
Do Sung Huh ◽  
Sang Joon Choe
Keyword(s):  
Density Functional Theory ◽  
Standard Deviation ◽  
Density Functional ◽  
Visible Spectrum ◽  
Mean Value ◽  
Time Dependent ◽  
Dft Methods ◽  
Functional Theory ◽  
Td Dft ◽  
The Mean

The recent interest in the application of density functional theory (DFT) has prompted us to test several functions in molecular geometries of methyl pheophorbides-a (MPa), an important starting material in photodynamic therapy (PDT). In this study, we report on tests for three popular DFT methods: M06-2X, B3LYP, and LSDA. Based on the standard deviation and the mean value, and by using the difference between optimized calculated value and experimental value in geometries, we drew the following conclusions: M06-2X/6-311+G(d,p) attained the smallest standard deviation of difference among the tested DFT methods in terms of bond length, whereas the standard deviation of bond angle in LSDA/6-311+G(d,p) was the smallest. In terms of absolute value, the mean value of LSDA/6-311+G(d,p) calculation was larger than that of M06-2X/6-311+G(d,p). We found that M06-2X/6-311+G(d,p) gave the best performance for MPa in the molecular geometries. The UV-visible spectrum was calculated with time-dependent density-functional theory (TD-DFT). Time-dependent M06-2X/6-311+G(d,p) gave the best performance for MPa in CH2Cl2 solution. In general, TD-DFT calculations in CH2Cl2 solution were more red-shifted compared with those in the solid state.

scholarly journals The Trip to the Density Functional Theory Zoo Continues: Making a Case for Time-Dependent Double Hybrids for Excited-State Problems

2021 ◽  
Vol 74 (1) ◽  
pp. 3 ◽  
Author(s):  
Lars Goerigk ◽  
Marcos Casanova-Paéz
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Organic Molecules ◽  
Real Life ◽  
Time Dependent ◽  
Electronic Excitations ◽  
Dft Methods ◽  
Functional Theory ◽  
Main Emphasis ◽  
Td Dft

This account is written for general users of time-dependent density functional theory (TD-DFT) methods as well as chemists who are unfamiliar with the field. It includes a brief overview of conventional TD-DFT approaches and recommendations for applications to organic molecules based on our own experience. The main emphasis of this work, however, lies in providing the first in-depth review of time-dependent double-hybrid density functionals. They were first established in 2007 with very promising follow-up studies in the subsequent four years before developments or applications became scarce. The topic has regained more interest since 2017, and this account reviews those latest developments led by our group. These developments have shown unprecedented robustness for a variety of different types of electronic excitations when compared to more conventional TD-DFT methods. In particular, time-dependent double hybrids do not suffer from artificial ghost states and are able to reproduce exciton-coupled absorption spectra. Our latest methods include range separation and belong to the currently best TD-DFT methods for singlet-singlet excitations in organic molecules. While there is still room for improvement and further development in this space, we hope that this account encourages users to adjust their computational protocols to such new methods to provide more real-life testing and scenarios.

Luminescent Re(i) terpyridine complexes for OLEDs: what does the DFT/TD-DFT probe reveal?

2015 ◽  
Vol 44 (18) ◽  
pp. 8529-8542 ◽  
Author(s):  
Gunasekaran Velmurugan ◽  
Ponnambalam Venuvanalingam
Keyword(s):  
Density Functional Theory ◽  
Electronic Structure ◽  
Density Functional ◽  
Spectroscopic Properties ◽  
Time Dependent ◽  
Dft Methods ◽  
Functional Theory ◽  
Td Dft ◽  
Dependent Density

The electronic structure and spectroscopic properties of a series of rhenium(i) terpyridine complexes were investigated using density functional theory (DFT) and time dependent density functional theory (TD-DFT) methods.

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)...

The effect of D–[De–π–A]n (n = 1, 2, 3) type dyes on the overall performance of DSSCs: a theoretical investigation

2017 ◽  
Vol 5 (30) ◽  
pp. 7510-7520 ◽  
Author(s):  
Ling-Jun He ◽  
Wei Wei ◽  
Jie Chen ◽  
Ran Jia ◽  
Jian Wang ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Theoretical Investigation ◽  
Density Functional ◽  
Organic Dyes ◽  
Time Dependent ◽  
Functional Theory ◽  
Td Dft ◽  
Overall Performance

A series of D–[De–π–A]n (n = 1, 2, 3) organic dyes have been theoretically investigated by means of density functional theory (DFT) and time-dependent DFT (TD-DFT) approaches.

The optical and electronic properties of graphene quantum dots with oxygen-containing groups: a density functional theory study

2017 ◽  
Vol 5 (24) ◽  
pp. 5984-5993 ◽  
Author(s):  
Jianguang Feng ◽  
Hongzhou Dong ◽  
Liyan Yu ◽  
Lifeng Dong
Keyword(s):  
Density Functional Theory ◽  
Quantum Dots ◽  
Density Functional ◽  
Graphene Quantum Dots ◽  
Time Dependent ◽  
Density Functional Theory Study ◽  
Functional Theory ◽  
Optical And Electronic Properties ◽  
Td Dft ◽  
Dependent Density

The effects of five types of oxygen-containing functional groups (–COOH, –COC–, –OH, –CHO, and –OCH3) on graphene quantum dots (GQDs) are investigated using time-dependent density functional theory (TD-DFT).

scholarly journals The structure and UV spectroscopy of benzene–water (Bz–W6) clusters using time-dependent density functional theory

2014 ◽  
Vol 13 (11) ◽  
pp. 1549-1560 ◽  
Author(s):  
Divya Sharma ◽  
Martin J. Paterson
Keyword(s):  
Density Functional Theory ◽  
Charge Transfer ◽  
Electronic Spectra ◽  
Water Cluster ◽  
Density Functional ◽  
Uv Spectroscopy ◽  
Time Dependent ◽  
Functional Theory ◽  
Td Dft ◽  
Dependent Density

MP2, DFT and TD-DFT applied to benzene–(water)6 clusters show how both perturb the electronic spectra of each other and give rise to new charge transfer features from the benzene to the water cluster.

The Photoluminescence Properties of the Alkali Metals Functionalized Adamantane Studied by Using Linear-Response Time-Dependent Density Functional Theory (TD-DFT) Calculations

2015 ◽  
Vol 1131 ◽  
pp. 117-122
Author(s):  
Nikorn Shinsuphan ◽  
Sriprajak Krongsuk ◽  
Vittaya Amornkitbamrung
Keyword(s):  
Density Functional Theory ◽  
Alkali Metal ◽  
Density Functional ◽  
Stokes Shift ◽  
Time Dependent ◽  
Photoluminescence Properties ◽  
Functional Theory ◽  
Absorption And Emission ◽  
Td Dft ◽  
Dependent Density

The photoluminescence properties of pristine adamantane molecule have been calculated by time-dependent density functional theory (TD-DFT) within the hybrid functional level. This study aims to investigate the luminescence properties of the pristine adamantane molecule and its functionalized with neutral and ion of alkali metal to form C10H16-nXn structure (where X is Li, Li+, Na and Na+ atoms, n=1). The electronic gap of the pristine adamantane (7.15 eV) is too wide, leading to an insulator property. While all the functionalized adamantanes exhibit semiconducting behavior. The absorption and emission energies of the original structure are 6.51 eV and 5.63 eV, respectively which are in good agreement with experimental results. The pure adamantane exhibits a broad photoluminescence peak in the ultraviolet region (UV). The Stokes shift of the transition between vertical and emission is 0.88 eV which agrees well with the previous work that measures the Stokes shift of 0.7 eV. The modification of adamantane indicates that the absorption and emission gaps substantially decreases. Substituting with alkali metal causes the photoluminescence onset can be shifted from the UV to the near-IR region. These results suggest that pure and the alkali metal functionalized adamantane molecules are promoting as candidate materials for the opto-electronic applications in the ultraviolet to infrared spectral regions.

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