scholarly journals Modeling of laser-pulse induced water decomposition on two-dimensional materials by simulations based on time-dependent density functional theory

2017 ◽  
Vol 96 (11) ◽  
Author(s):  
Yoshiyuki Miyamoto ◽  
Hong Zhang ◽  
Xinlu Cheng ◽  
Angel Rubio
Keyword(s):  
Density Functional Theory ◽  
Laser Pulse ◽  
Density Functional ◽  
Time Dependent ◽  
Two Dimensional ◽  
Water Decomposition ◽  
Functional Theory ◽  
Two Dimensional Materials ◽  
Dependent Density

Nonperturbative time-dependent density functional theory (TDDFT) and time-dependent electron localization function (TDELF) study of the ionization of OCS and CS2 with ultrashort intense laser pulses — Orientational effects

2012 ◽  
Vol 90 (7) ◽  
pp. 616-624 ◽  
Author(s):  
Emmanuel Fowe Penka ◽  
André Dieter Bandrauk
Keyword(s):  
Density Functional Theory ◽  
Laser Pulse ◽  
Density Functional ◽  
Laser Pulses ◽  
Time Dependent ◽  
Intense Laser ◽  
Electron Localization ◽  
Functional Theory ◽  
Intense Laser Pulses ◽  
Dependent Density

The nonlinear nonperturbative response of OCS and CS2 to ultrashort (few cycles) intense laser pulses was studied numerically by time-dependent density functional theory (TDDFT) methods to understand molecular ionization as a function of laser–molecule orientation. A time-dependent electron localization function(TDELF) was used to visualize the nonlinear nonperturbative electron transfer occurring during the laser pulse. It was found that, for intensities I > 3.5 × 1014 W/cm2, the inner shell Kohn–Sham (KS) molecular orbitals contribute significantly to the ionization, whereas for the intensity I < 3.5 × 1014 W/cm2, the highest occupied molecular orbital (HOMO) shows the dominant response to the field. In general, the ionization rate maxima correspond to the alignment of maximum KS orbital densities with the laser pulse polarization instead of orbital ionization potentials (IP). These findings are corroborated through analysis of the TDELF images, where the ionization occurs from the lone pair or bond regions of the corresponding molecules.

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>

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