Non-equilibrium dynamics from RPMD and CMD

CORC > 化学研究所 > 中国科学院化学研究所 > 分子动态与稳态结构实验室

	Non-equilibrium dynamics from RPMD and CMD
	Welsch, Ralph 1; Song, Kai 2; Shi, Qiang 2; Althorpe, Stuart C.3; Miller, Thomas F., III 1
刊名	JOURNAL OF CHEMICAL PHYSICS
	2016-11-28
卷号	145 期号:20
英文摘要	We investigate the calculation of approximate non-equilibrium quantum time correlation functions (TCFs) using two popular path-integral-based molecular dynamics methods, ring-polymer molecular dynamics (RPMD) and centroid molecular dynamics (CMD). It is shown that for the cases of a sudden vertical excitation and an initial momentum impulse, both RPMD and CMD yield non-equilibrium TCFs for linear operators that are exact for high temperatures, in the t = 0 limit, and for harmonic potentials; the subset of these conditions that are preserved for non-equilibrium TCFs of non-linear operators is also discussed. Furthermore, it is shown that for these non-equilibrium initial conditions, both methods retain the connection to Matsubara dynamics that has previously been established for equilibrium initial conditions. Comparison of non-equilibrium TCFs from RPMD and CMD to Matsubara dynamics at short times reveals the orders in time to which the methods agree. Specifically, for the position-autocorrelation function associated with sudden vertical excitation, RPMD and CMD agree with Matsubara dynamics up to O (t(4)) and O (t(1)), respectively; for the position-autocorrelation function associated with an initial momentum impulse, RPMD and CMD agree with Matsubara dynamics up to O (t(5)) and O (t(2)), respectively. Numerical tests using model potentials for a wide range of non-equilibrium initial conditions show that RPMD and CMD yield non-equilibrium TCFs with an accuracy that is comparable to that for equilibrium TCFs. RPMD is also used to investigate excited-state proton transfer in a system-bath model, and it is compared to numerically exact calculations performed using a recently developed version of the Liouville space hierarchical equation of motion approach; again, similar accuracy is observed for non-equilibrium and equilibrium initial conditions. Published by AIP Publishing.
语种	英语
内容类型	期刊论文
源URL	[http://ir.iccas.ac.cn/handle/121111/38009]
专题	化学研究所_分子动态与稳态结构实验室
作者单位	1.CALTECH, Div Chem & Chem Engn, 1200 E Calif Blvd, Pasadena, CA 91125 USA 2.Chinese Acad Sci, Beijing Natl Lab Mol Sci, State Key Lab Struct Chem Unstable & Stable Speci, Inst Chem, Beijing 100190, Peoples R China 3.Univ Cambridge, Dept Chem, Lensfield Rd, Cambridge CB2 1EW, England
推荐引用方式 GB/T 7714	Welsch, Ralph,Song, Kai,Shi, Qiang,et al. Non-equilibrium dynamics from RPMD and CMD[J]. JOURNAL OF CHEMICAL PHYSICS,2016,145(20).
APA	Welsch, Ralph,Song, Kai,Shi, Qiang,Althorpe, Stuart C.,&Miller, Thomas F., III.(2016).Non-equilibrium dynamics from RPMD and CMD.JOURNAL OF CHEMICAL PHYSICS,145(20).
MLA	Welsch, Ralph,et al."Non-equilibrium dynamics from RPMD and CMD".JOURNAL OF CHEMICAL PHYSICS 145.20(2016).