Time-Dependent Kinetic-Thermodynamic Description of a Nonequilibrium Molecular System: The HF Chemical Laser

1979 ◽  
pp. 22-25
Author(s):  
A. Ben-Shaul ◽  
O. Kafri ◽  
R. D. Levine
Keyword(s):  
Molecular System ◽  
Thermodynamic Description ◽  
Time Dependent ◽  
Chemical Laser

Time-dependent oscillations in a cw chemical laser unstable resonator

1985 ◽  
Vol 24 (21) ◽  
pp. 3598 ◽  
Author(s):  
Lee H. Sentman ◽  
Munir H. Nayfeh ◽  
Steven W. Townsend ◽  
Kevin King ◽  
Gus Tsioulos ◽  
...  
Keyword(s):  
Time Dependent ◽  
Unstable Resonator ◽  
Chemical Laser

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.

scholarly journals Internal Degrees of Freedom and Anelasticity in Glasses

1980 ◽  
Vol 33 (3) ◽  
pp. 573 ◽  
Author(s):  
DA Smith ◽  
P Cookson
Keyword(s):  
Degrees Of Freedom ◽  
Ultrasonic Attenuation ◽  
Thermodynamic Description ◽  
Irreversible Thermodynamics ◽  
Time Dependent ◽  
Time Varying ◽  
Thermally Activated ◽  
The Matrix ◽  
After Effect ◽  
Internal Degrees Of Freedom

An extension of the AHV-Phillips model is proposed which describes the anelastic and timedependent behaviour of glasses over a range of temperatures. The model assumes the existence of g;roups of atoms with two or more metastable locations in the matrix. Transitions between these locations are assumed to be thermally activated, and the parameters of the potential seen by such groups are assumed to be continuously distributed. The active groups are a realization of internal degrees of freedom in the sense of irreversible thermodynamics. The thermodynamic description is particularly convenient when strain couplings are involved, since Maxwell relations determine the internal contribution ,to the stress in terms of the strain dependence of the internal potentials. Several consequences of the model, such as time-dependent heat capacities, time-varying stress-strain relations etc., are investigated and found to be consistent with existing experiments. In particular, Wiedmann's elastic after-effect measurements of 1886 can be fitted and lead to values of 0�6-0�9 eV for the width of the distribution of energy barriers. However, the predicted ultrasonic attenuation from active groups conflicts with experiment, and reasons for this are discussed.

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