Time-dependent generalization of the Nosé-Hoover thermostatting technique for molecular dynamics simulations

2nd International Conference on Mathematical Modeling in Physical Sciences 2013

物理学;数学

Davis, Edward D.^1 ; Zaher, Ashraf A.^2

Department of Physics, Faculty of Science, Kuwait University, Safat 13060, Kuwait^1

Department of Electrical and Computer Engineering, College of Arts and Sciences, American University of Kuwait, PO Box 3323, Safat 13034, Kuwait^2

关键词: Constant temperature;    Graphical programming;    Harmonic oscillators;    Matlab Simulink platform;    Molecular dynamics simulations;    Momentum distributions;    Non-autonomous system;    Time-dependent functions;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/490/1/012101/pdf
DOI  :  10.1088/1742-6596/490/1/012101

来源: IOP

【 摘 要 】

The Nose´-Hoover scheme demonstrates that molecular dynamics simulations can be used to calculate the properties of systems at constant temperature (i.e. canonical ensemble averages). There is interest in deterministic generalizations of Nose´-Hoover dynamics which are ergodic even for simple systems like the harmonic oscillator. Prompted by parallels with studies of the Duffing oscillator within control theory, we have investigated a non-autonomous version of the Nose´-Hoover oscillator in which the temperature is replaced by a weakly time-dependent function. This function is chosen so that its average over time coincides with the temperature desired. Calculations are facilitated by graphical programming with a MATLAB-Simulink platform. A time series analysis of our simple non-autonomous system yields the position and momentum distributions expected for the harmonic oscillator.