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

2012 ◽  
Vol 2012 ◽  
pp. 1-11 ◽  
Author(s):  
Robert J. Hinde

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.

Author(s):  
Ming-Lei Shao ◽  
Rui-Jun Yan ◽  
Jing Wu ◽  
Ji-Yeong Lee ◽  
Chang-Soo Han ◽  
...  

We present a new roadmap based on a generalized Voronoi graph for two-identical-link mobile robots to explore an unknown planar environment. It is called the L2-generalized Voronoi graph and is defined in terms of workspace distance measurements using only sensor-provided information, with the robot having the maximum distance from obstacles, and is therefore optimum in a point of view for exploration and obstacle avoidance. The configuration of the robot possesses four degrees of freedom, and hence the roadmap is one-dimensional in an unknown configuration space [Formula: see text]. The L2-generalized Voronoi graph is not always connected, and so is connected with an additional structure called the L2R-edge, where the robot is tangent to a GVD structure with the same orientation for the two links. This roadmap is termed L2 hierarchical generalized Voronoi graph. The L2 hierarchical generalized Voronoi graph includes two structures: the L2 hierarchical generalized Voronoi graph and the L2R edge. Although the condition of two identical links looks somewhat constraining, the L2 hierarchical generalized Voronoi graph is still worth pursuing because the case is very common in the engineering environment.


2019 ◽  
Author(s):  
Riccardo Spezia ◽  
Hichem Dammak

<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>


2021 ◽  
Author(s):  
Lixiang Han ◽  
Mengmeng Yang ◽  
Peiting Wen ◽  
Wei Gao ◽  
nengjie huo ◽  
...  

One dimensional (1D)-two dimensional (2D) van der Waals (vdWs) mixed-dimensional heterostructures with advantages of atomically sharp interface, high quality and good compatibility have attracted tremendous attention in recent years. The...


Author(s):  
Zhibin Liu ◽  
Keda Ding ◽  
Zhifu Liu ◽  
Faqiang Zhang ◽  
Huarong Zeng ◽  
...  

2013 ◽  
Vol 117 (13) ◽  
pp. 6800-6806 ◽  
Author(s):  
M. Jafary-Zadeh ◽  
C. D. Reddy ◽  
Yong-Wei Zhang

2002 ◽  
Vol 42 (3) ◽  
pp. 272-278 ◽  
Author(s):  
Tait S. Smith ◽  
Brian K. Bay ◽  
Mark M. Rashid

2014 ◽  
Vol 687-691 ◽  
pp. 610-615 ◽  
Author(s):  
Hui Liu ◽  
Li Wen Guan

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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