scholarly journals Density Functional Theory and Time-Dependent Density-Functional Study of Positively Charged Alkali Metal Doped Stone Whale Defective Graphene Complexes

2015 ◽  
Vol 27 (1) ◽  
pp. 129-133
Author(s):  
Bin Huang ◽  
Cui Zhen Li ◽  
Guo Ping Zhu
2010 ◽  
Vol 24 (24) ◽  
pp. 4811-4820
Author(s):  
Y. P. ZHANG ◽  
F. S. ZHANG ◽  
Y. GAO ◽  
H. W. CHANG ◽  
G. Q. XIAO

The process of multielectron transfer from a Na 4 cluster induced by highly charged C 6+, C 4+, C 2+ and C + ions is studied using the method of time-dependent density functional theory within the local density approximation combined with the use of pseudopotential. The evolution of dipole moment changes and emitted electrons in Na 4 is obtained and the time-dependent probabilities with various charges are deduced. It is shown that the Na 4 cluster is strongly ionized by C 6+ and that the number of emitted electrons per atom of Na 4 is larger than that of Na 2 under the same condition. One can find that the detailed information of the emitted electrons from Na 4 is different from the same from Na 2, which is possibly related to the difference in structure between the two clusters.


2015 ◽  
Vol 1131 ◽  
pp. 117-122
Author(s):  
Nikorn Shinsuphan ◽  
Sriprajak Krongsuk ◽  
Vittaya Amornkitbamrung

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.


2019 ◽  
Author(s):  
Kamal Batra ◽  
Stefan Zahn ◽  
Thomas Heine

<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>


Author(s):  
Huimin Guo ◽  
Xiaolin Ma ◽  
Zhiwen Lei ◽  
Yang Qiu ◽  
Bernhard Dick ◽  
...  

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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