Generalized discrete truncated Wigner approximation for nonadiabatic quantum-classical dynamics
Year: 2021
Authors: Lang H., Vendrell O., Hauke P.
Autors Affiliation: Heidelberg Univ, Inst Phys Chem, Theoret Chem, Neuenheimer Feld 229, D-69120 Heidelberg, Germany; Univ Trento, INO CNR BEC Ctr, Via Sommar 14, I-38123 Trento, Italy; Univ Trento, Dept Phys, Via Sommar 14, I-38123 Trento, Italy.
Abstract: Nonadiabatic molecular dynamics occur in a wide range of chemical reactions and femtochemistry experiments involving electronically excited states. These dynamics are hard to treat numerically as the system?s complexity increases, and it is thus desirable to have accurate yet affordable methods for their simulation. Here, we introduce a linearized semiclassical method, the generalized discrete truncated Wigner approximation (GDTWA), which is well-established in the context of quantum spin lattice systems, into the arena of chemical nonadiabatic systems. In contrast to traditional continuous mapping approaches, e.g., the Meyer-Miller-Stock-Thoss and the spin mappings, GDTWA samples the electron degrees of freedom in a discrete phase space and thus forbids an unphysical unbounded growth of electronic state populations. The discrete sampling also accounts for an effective reduced but non-vanishing zero-point energy without an explicit parameter, which makes it possible to treat the identity operator and other operators on an equal footing. As numerical benchmarks on two linear vibronic coupling models and Tully?s models show, GDTWA has a satisfactory accuracy in a wide parameter regime, independent of whether the dynamics is dominated by relaxation or by coherent interactions. Our results suggest that the method can be very adequate to treat challenging nonadiabatic dynamics problems in chemistry and related fields.
Journal/Review: JOURNAL OF CHEMICAL PHYSICS
Volume: 155 (2) Pages from: 024111-1 to: 024111-11
More Information: We acknowledge support from Provincia Autonoma di Trento, the ERC Starting Grant StrEnQTh (Project No. 804305), and Q@TN-Quantum Science and Technology in Trento. H.L. thanks Hans-Dieter Meyer and Markus Schroder for assistance with the MCTDH simulations.KeyWords: zero-point energy; molecular-dynamics; phase-space; semiclassical description; electronic degreesDOI: 10.1063/5.0054696Citations: 8data from “WEB OF SCIENCE” (of Thomson Reuters) are update at: 2024-10-27References taken from IsiWeb of Knowledge: (subscribers only)Connecting to view paper tab on IsiWeb: Click hereConnecting to view citations from IsiWeb: Click here