---
res:
  bibo_abstract:
  - Dynamic processes in molecules can occur on a wide range of timescales, and it
    is important to understand which timescales of motion contribute to different
    parameters used in dynamics measurements. For spin relaxation, this can easily
    be understood from the sampling frequencies of the spectral-density function by
    different relaxation-rate constants. In addition to data from relaxation measurements,
    determining dynamically averaged anisotropic interactions in magic-angle spinning
    (MAS) solid-state NMR allows for better quantification of the amplitude of molecular
    motion. For partially averaged anisotropic interactions, the relevant timescales
    of motion are not so clearly defined. Whether the averaging depends on the experimental
    methods (e.g., pulse sequences) or conditions (e.g., MAS frequency, magnitude
    of anisotropic interaction, radio-frequency field amplitudes) is not fully understood.
    To investigate these questions, we performed numerical simulations of dynamic
    systems based on the stochastic Liouville equation using several experiments for
    recoupling the dipolar coupling, chemical-shift anisotropy or quadrupolar coupling.
    As described in the literature, the transition between slow motion, where parameters
    characterizing the anisotropic interaction are not averaged, and fast motion,
    where the tensors are averaged leading to a scaled anisotropic quantity, occurs
    over a window of motional rate constants that depends mainly on the strength of
    the interaction. This transition region can span 2 orders of magnitude in exchange-rate
    constants (typically in the microsecond range) but depends only marginally on
    the employed recoupling scheme or sample spinning frequency. The transition region
    often coincides with a fast relaxation of coherences, making precise quantitative
    measurements difficult. Residual couplings in off-magic-angle experiments, however,
    average over longer timescales of motion. While in principle one may gain information
    on the timescales of motion from the transition area, extracting such information
    is hampered by low signal-to-noise ratio in experimental spectra due to fast relaxation
    that occurs in the same region.@eng
  bibo_authorlist:
  - foaf_Person:
      foaf_givenName: Kathrin
      foaf_name: Aebischer, Kathrin
      foaf_surname: Aebischer
  - foaf_Person:
      foaf_givenName: Lea Marie
      foaf_name: Becker, Lea Marie
      foaf_surname: Becker
      foaf_workInfoHomepage: http://www.librecat.org/personId=36336939-eb97-11eb-a6c2-c83f1214ca79
    orcid: 0000-0002-6401-5151
  - foaf_Person:
      foaf_givenName: Paul
      foaf_name: Schanda, Paul
      foaf_surname: Schanda
      foaf_workInfoHomepage: http://www.librecat.org/personId=7B541462-FAF6-11E9-A490-E8DFE5697425
    orcid: 0000-0002-9350-7606
  - foaf_Person:
      foaf_givenName: Matthias
      foaf_name: Ernst, Matthias
      foaf_surname: Ernst
  bibo_doi: 10.5194/mr-5-69-2024
  bibo_issue: '1'
  bibo_volume: 5
  dct_date: 2024^xs_gYear
  dct_isPartOf:
  - http://id.crossref.org/issn/2699-0016
  dct_language: eng
  dct_publisher: Copernicus Publications@
  dct_title: Evaluating the motional timescales contributing to averaged anisotropic
    interactions in MAS solid-state NMR@
  fabio_hasPubmedId: '40384772'
...