Density of States of One-Dimensional Hindered Internal Rotors and Separability of Rotational Degrees of Freedom

1998 ◽  
Vol 102 (22) ◽  
pp. 3916-3922 ◽  
Author(s):  
Vadim D. Knyazev
Keyword(s):  
Density Of States ◽  
Degrees Of Freedom ◽  
One Dimensional ◽  
Rotational Degrees Of Freedom

scholarly journals Electronic-Rotational Coupling in Cl–para-H2 Van der Waals Dimers

2012 ◽  
Vol 2012 ◽  
pp. 1-11 ◽  
Author(s):  
Robert J. Hinde
Keyword(s):  
Configuration Space ◽  
Degrees Of Freedom ◽  
Van Der Waals ◽  
Open Shell ◽  
Hamiltonian Matrix ◽  
Weakly Bound ◽  
One Dimensional ◽  
Rotational Degrees Of Freedom ◽  
Rotational Coupling ◽  
Cl Atom

We examine the interaction between an open-shell chlorine atom and a para-H2 molecule in the region of configuration space that corresponds to a weakly bound Cl–para-H2 van der Waals dimer. By constructing and diagonalizing the Hamiltonian matrix that represents the coupled Cl atom electronic and H2 rotational degrees of freedom, we obtain one-dimensional energy curves for the Cl–para-H2 system in this region of configuration space. We find that the dimer exhibits fairly strong electronic-rotational coupling when the Cl–H2 distance R is close to ; however, this coupling does not modify substantially the positions and depths of the van der Waals wells in the dimer’s curves. An approximation in which the para-H2 fragment is treated in the strict limit thus appears to yield an accurate representation of those states of the weakly bound Cl–para-H2 dimer that correlate with H2 in the limit.

On the Use of Quantum Thermal Bath in Unimolecular Fragmentation Simulations

2019 ◽  
Author(s):  
Riccardo Spezia ◽  
Hichem Dammak
Keyword(s):  
Degrees Of Freedom ◽  
Molecular Simulations ◽  
Zero Point ◽  
Thermal Bath ◽  
Unimolecular Dissociation ◽  
Point Energy ◽  
Rotational Degrees Of Freedom ◽  
The Difference ◽  
Nuclear Effects

<div> <div> <div> <p>In the present work we have investigated the possibility of using the Quantum Thermal Bath (QTB) method in molecular simulations of unimolecular dissociation processes. Notably, QTB is aimed in introducing quantum nuclear effects with a com- putational time which is basically the same as in newtonian simulations. At this end we have considered the model fragmentation of CH4 for which an analytical function is present in the literature. Moreover, based on the same model a microcanonical algorithm which monitor zero-point energy of products, and eventually modifies tra- jectories, was recently proposed. We have thus compared classical and quantum rate constant with these different models. QTB seems to correctly reproduce some quantum features, in particular the difference between classical and quantum activation energies, making it a promising method to study unimolecular fragmentation of much complex systems with molecular simulations. The role of QTB thermostat on rotational degrees of freedom is also analyzed and discussed. </p> </div> </div> </div>

Effect of Rotational Degrees of Freedom on Molecular Mobility

2013 ◽  
Vol 117 (13) ◽  
pp. 6800-6806 ◽  
Author(s):  
M. Jafary-Zadeh ◽  
C. D. Reddy ◽  
Yong-Wei Zhang
Keyword(s):  
Molecular Mobility ◽  
Degrees Of Freedom ◽  
Rotational Degrees Of Freedom

Dynamic Modeling of a High-Dynamic Flight Simulator

2014 ◽  
Vol 687-691 ◽  
pp. 610-615 ◽  
Author(s):  
Hui Liu ◽  
Li Wen Guan
Keyword(s):  
Dynamic Modeling ◽  
Degrees Of Freedom ◽  
Flight Simulator ◽  
Inverse Dynamic ◽  
Dynamic Formulation ◽  
Time Histories ◽  
Rotational Degrees Of Freedom ◽  
High Dynamic ◽  
Euler Approach ◽  
Simulation Results

High-dynamic flight simulator (HDFS), using a centrifuge as its motion base, is a machine utilized for simulating the acceleration environment associated with modern advanced tactical aircrafts. This paper models the HDFS as a robotic system with three rotational degrees of freedom. The forward and inverse dynamic formulations are carried out by the recursive Newton-Euler approach. The driving torques acting on the joints are determined on the basis of the inverse dynamic formulation. The formulation has been implemented in two numerical simulation examples, which are used for calculating the maximum torques of actuators and simulating the time-histories of kinematic and dynamic parameters of pure trapezoid Gz-load command profiles, respectively. The simulation results can be applied to the design of the control system. The dynamic modeling approach presented in this paper can also be generalized to some similar devices.

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