Accelerating ring-polymer molecular dynamics with parallel-replica dynamics

Journal Article · Tue Jun 28 04:00:00 EDT 2016 · Journal of Chemical Physics

DOI:https://doi.org/10.1063/1.4954311· OSTI ID:22676003

Lu, Chun-Yaung ^[1]; Perez, Danny

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1. Department of Energy Resources Engineering, Stanford University, Stanford, CA 94305 (United States)

Nuclear quantum effects are important for systems containing light elements, and the effects are more prominent in the low temperature regime where the dynamics also becomes sluggish. We show that parallel replica (ParRep) dynamics, an accelerated molecular dynamics approach for infrequent-event systems, can be effectively combined with ring-polymer molecular dynamics, a semiclassical trajectory approach that gives a good approximation to zero-point and tunneling effects in activated escape processes. The resulting RP-ParRep method is a powerful tool for reaching long time scales in complex infrequent-event systems where quantum dynamics are important. Two illustrative examples, symmetric Eckart barrier crossing and interstitial helium diffusion in Fe and Fe–Cr alloy, are presented to demonstrate the accuracy and long-time scale capability of this approach.

• OSTI ID: 22676003
• Journal Information: Journal of Chemical Physics, Journal Name: Journal of Chemical Physics Journal Issue: 24 Vol. 144; ISSN JCPSA6; ISSN 0021-9606
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
COMPUTERIZED SIMULATION
MOLECULAR DYNAMICS METHOD
POLYMERS
SEMICLASSICAL APPROXIMATION
TEMPERATURE RANGE 0065-0273 K
TUNNEL EFFECT