Reducing dynamical electron scattering reveals hydrogen atoms.
Max T B ClabbersTim GrueneEric van GenderenJan Pieter AbrahamsPublished in: Acta crystallographica. Section A, Foundations and advances (2019)
Compared with X-rays, electron diffraction faces a crucial challenge: dynamical electron scattering compromises structure solution and its effects can only be modelled in specific cases. Dynamical scattering can be reduced experimentally by decreasing crystal size but not without a penalty, as it also reduces the overall diffracted intensity. In this article it is shown that nanometre-sized crystals from organic pharmaceuticals allow positional refinement of the hydrogen atoms, even whilst ignoring the effects of dynamical scattering during refinement. To boost the very weak diffraction data, a highly sensitive hybrid pixel detector was employed. A general likelihood-based computational approach was also introduced for further reducing the adverse effects of dynamic scattering, which significantly improved model accuracy, even for protein crystal data at substantially lower resolution.
Keyphrases
- density functional theory
- monte carlo
- electron microscopy
- electronic health record
- emergency department
- big data
- mass spectrometry
- machine learning
- molecular dynamics
- amino acid
- magnetic resonance
- solid state
- high resolution
- small molecule
- crystal structure
- protein protein
- data analysis
- artificial intelligence
- ionic liquid
- binding protein
- room temperature
- water soluble
- adverse drug