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Title: Communication: Probing anomalous diffusion in frequency space

Journal Article · · Journal of Chemical Physics
DOI:https://doi.org/10.1063/1.4936129· OSTI ID:22493242
 [1]
  1. Centre de Biophys. Moléculaire, CNRS, Rue Charles Sadron, 45071 Orléans (France)

Anomalous diffusion processes are usually detected by analyzing the time-dependent mean square displacement of the diffusing particles. The latter evolves asymptotically as W(t) ∼ 2D{sub α}t{sup α}, where D{sub α} is the fractional diffusion constant and 0 < α < 2. In this article we show that both D{sub α} and α can also be extracted from the low-frequency Fourier spectrum of the corresponding velocity autocorrelation function. This offers a simple method for the interpretation of quasielastic neutron scattering spectra from complex (bio)molecular systems, in which subdiffusive transport is frequently encountered. The approach is illustrated and validated by analyzing molecular dynamics simulations of molecular diffusion in a lipid POPC bilayer.

OSTI ID:
22493242
Journal Information:
Journal of Chemical Physics, Vol. 143, Issue 19; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-9606
Country of Publication:
United States
Language:
English