SIMULATIONS OF PUMP-PROBE EXCITATIONS OF ELECTRONIC WAVE PACKETS FOR A LARGE QUASI-RIGID MOLECULAR SYSTEM BY MEANS OF AN EXTENSION TO THE TIME-DEPENDENT CONFIGURATION INTERACTION SINGLES METHOD

2013 ◽  
Vol 12 (03) ◽  
pp. 1350005 ◽  
Author(s):  
STEFAN KLINKUSCH ◽  
TILLMANN KLAMROTH
Keyword(s):  
Wave Packet ◽  
Configuration Interaction ◽  
Molecular System ◽  
Wave Packets ◽  
Test System ◽  
Time Dependent ◽  
Basis Sets ◽  
Probe Laser ◽  
Experimental Realization ◽  
Pump Probe

In this paper, we report simulations of laser-driven many-electron dynamics by means of the time-dependent configuration interaction singles (TD-CIS) approach. Photoionization is included by a heuristic model within calculations employing standard Gaussian basis sets. Benzo[g]-N-methyl-quinolinium-7-hydroxylate (BMQ7H) serves as a test system to generate predefined wave packets, i.e. a superposition between the ground and fifth excited state, in a large molecule. For this molecule, these two states have a very similar geometry, which enables us to use the fixed nuclei approximation. Furthermore, this geometric stability would also prevent a dephasing of the electron wave packet due to nuclear dynamics in an experimental realization of our simulations. We also simulate the possible detection of such a wave packet by ultra short probe laser pulses, i.e. pump-probe spectra.

CONTROLLING WAVE PACKET INTERFERENCE OF DISSOCIATING MOLECULES BY SHAPING LASER PULSES IN FREQUENCY DOMAIN

2008 ◽  
Vol 07 (06) ◽  
pp. 1159-1169 ◽  
Author(s):  
YONG-CHANG HAN ◽  
KAI-JUN YUAN ◽  
SHU-LIN CONG
Keyword(s):  
Wave Packet ◽  
Frequency Domain ◽  
Laser Field ◽  
Wave Packets ◽  
Laser Pulses ◽  
Time Dependent ◽  
Pulse Excitation ◽  
Density Functions ◽  
Excitation Scheme ◽  
Quantum Wave

The interference of dissociating wave packets for the Br 2 molecule in femtosecond laser field is studied theoretically using time-dependent quantum wave packet method. The interference of dissociating wave packets can be determined by the spectrum of laser field. By shaping laser pulses in frequency domain, the corresponding R- and v-dependent density functions can be effectively controlled. Compared with the 2-pulse excitation scheme, the resolution of the interference patterns can be improved by using 3- and 4-pulse excitation schemes. The dissociating velocity can be steered by varying laser parameters.

Exact wave packet propagation using time‐dependent basis sets

1989 ◽  
Vol 90 (10) ◽  
pp. 5566-5577 ◽  
Author(s):  
J. Kucar ◽  
H.‐D. Meyer
Keyword(s):  
Wave Packet ◽  
Time Dependent ◽  
Basis Sets

Solving for Quantum Controls

2011 ◽  
Author(s):  
Katherine A. Kime
Keyword(s):  
Wave Packet ◽  
Potential Barrier ◽  
Wave Packets ◽  
Schroedinger Equation ◽  
Time Dependent ◽  
Single Peak ◽  
Double Peak ◽  
Quantum Wave ◽  
Dependent Potential

We study the use of a time-dependent potential barrier to control quantum wave packets, in a discretization of the Schroedinger equation. We consider computational issues in solving for a control which steers an initial single peak wave packet to a terminal double peak wave packet.

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>

The Spectrum Segmentation Algorithm of Multimode Vibration Signal Based on Spectral Clustering

2011 ◽  
Vol 121-126 ◽  
pp. 2372-2376
Author(s):  
Dan Dan Wang ◽  
Yu Zhou ◽  
Qing Wei Ye ◽  
Xiao Dong Wang
Keyword(s):  
Wave Packet ◽  
Frequency Domain ◽  
Spectral Clustering ◽  
Clustering Algorithm ◽  
Wave Packets ◽  
Vibration Signal ◽  
Segmentation Algorithm ◽  
Frequency Curve ◽  
Macroscopic Observation ◽  
Spectral Clustering Algorithm

The mode peaks in frequency domain of vibration signal are strongly interfered by strong noise, causing the inaccuracy mode parameters. According to this situation, this paper comes up with the thought of mode-peak segmentation based on the spectral clustering algorithm. First, according to the concept of wave packet, the amplitude-frequency of vibration signal is divided into wave packets. Taking each wave packet as a sample of clustering algorithm, the spectral clustering algorithm is used to classify these wave packets. The amplitude-frequency curve of a mode peak becomes a big wave packet in macroscopic. The experiment to simulation signals indicates that this spectral clustering algorithm could accord with the macroscopic observation of mode segmentation effectively, and has outstanding performance especially in strong noise.

Pump-Probe Laser Photolytic Fragmentation Fluorescence Spectrometry of Isomeric Alkenes

1994 ◽  
Vol 48 (5) ◽  
pp. 616-619 ◽  
Author(s):  
Bobby J. Stanton ◽  
E. T. Monroe ◽  
E. L. Wehry
Keyword(s):  
Fluorescence Intensity ◽  
Laser Fluence ◽  
Laser Wavelength ◽  
Fluorescence Spectrometry ◽  
Probe Laser ◽  
Intermediate Species ◽  
Pump Probe ◽  
Laser Pump ◽  
Photolysis Laser ◽  
Spectral Patterns

The two-laser “pump-probe” photolytic fragmentation fluorescence spectrometry of three octenes and two nonenes is described. Probe-laser-induced C2 fluorescence (Deslandres-d'Azambuja system, C1II g→ A1II u) is detected. The relative C2 fluorescence intensity and spectral patterns exhibited by each alkene are strongly dependent on the probe-laser wavelength. The dependence of the fragment fluorescence intensity on the probe-laser fluence implies that the “probe” laser induces photofragmentation of intermediate species produced by the “photolysis” laser.

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