Mixed quantum-classical simulations of charge transport in organic materials: Numerical benchmark of the Su-Schrieffer-Heeger model

Journal Article · Tue Jun 28 00:00:00 EDT 2011 · Journal of Chemical Physics

DOI:https://doi.org/10.1063/1.3604561· OSTI ID:21560310

Linjun, Wang; Beljonne, David ^[1]; Liping, Chen; Qiang, Shi ^[2]

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1. Laboratory for Chemistry of Novel Materials, University of Mons, Place du Parc 20, B-7000 Mons (Belgium)
2. State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Beijing National Laboratory for Molecular Sciences (BNLMS), Institute of Chemistry, Chinese Academy of Sciences, Zhongguancun, 100190 Beijing (China)

The electron-phonon coupling is critical in determining the intrinsic charge carrier and exciton transport properties in organic materials. In this study, we consider a Su-Schrieffer-Heeger (SSH) model for molecular crystals, and perform numerical benchmark studies for different strategies of simulating the mixed quantum-classical dynamics. These methods, which differ in the selection of initial conditions and the representation used to solve the time evolution of the quantum carriers, are shown to yield similar equilibrium diffusion properties. A hybrid approach combining molecular dynamics simulations of nuclear motion and quantum-chemical calculations of the electronic Hamiltonian at each geometric configuration appears as an attractive strategy to model charge dynamics in large size systems ''on the fly,'' yet it relies on the assumption that the quantum carriers do not impact the nuclear dynamics. We find that such an approximation systematically results in overestimated charge-carrier mobilities, with the associated error being negligible when the room-temperature mobility exceeds {approx}4.8 cm{sup 2}/Vs ({approx}0.14 cm{sup 2}/Vs) in one-dimensional (two-dimensional) crystals.

• OSTI ID: 21560310
• Journal Information: Journal of Chemical Physics, Vol. 134, Issue 24; Other Information: DOI: 10.1063/1.3604561; (c) 2011 American Institute of Physics; ISSN 0021-9606
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
APPROXIMATIONS
BENCHMARKS
CARRIER MOBILITY
CHARGE CARRIERS
CHARGE EXCHANGE
CHARGE TRANSPORT
DIFFUSION
ELECTRON-PHONON COUPLING
EQUILIBRIUM
ERRORS
EXCITONS
HAMILTONIANS
MOLECULAR CRYSTALS
MOLECULAR DYNAMICS METHOD
ONE-DIMENSIONAL CALCULATIONS
ORGANIC COMPOUNDS
ORGANIC MATTER
SIMULATION
CALCULATION METHODS
COUPLING
CRYSTALS
MATHEMATICAL OPERATORS
MATTER
MOBILITY
QUANTUM OPERATORS
QUASI PARTICLES