Further study of path integral Liouville dynamics

作者：Jian Liu, Xinzijian Liu, De-Zhang Li · 发表于：Scientia Sinica Chimica · 年份：2016 · DOI：10.1360/n032015-00143 · 被引用次数：9 · 研究领域：Quantum chaos and dynamical systems、Advanced Thermodynamics and Statistical Mechanics、Nonlinear Dynamics and Pattern Formation

Path integral Liouville dynamics (PILD) is a trajectory-based quantum dynamics approach that has the two important properties: conserves the quantum Boltzmann distribution and recovers exact thermal correlation functions (of even nonlinear operators) in the harmonic limit. In the article we show that PILD can be derived from equilibrium continuity dynamics, as well as originally from equilibrium Liouville dynamics or equilibrium Hamiltonian dynamics, when a global Gaussian momentum distribution is presented in the Wigner phase space density distribution function. It has been shown that the Staging transformation of the path integral beads offers a much more efficient sampling approach for evaluating the effective force in the free particle limit. When Langevin dynamics is employed as the thermostatting method in PILD, the optimum Langevin friction coefficient is suggested to be the same as the adiabatic frequency w ad and a more efficient algorithm (than the velocity Verlet) for integrating the PILD equations of motion is also proposed.