Quantitative Convergent Beam Electron Diffraction (QCBED) gives information on both structure factor phases and amplitudes. By using the observed intensity variations in the direct beam of a CBED pattern, selected structure factors and three-phase structure invariants are refined. The test case studied is an energy-filtered CBED pattern of InP tilted close to the 170 zone axis and recorded at liquid nitrogen temperature and 119.5 kV. In the QCBED refinements, the detailed structure of the specimen is assumed unknown, so neither phases nor accurate structure factor amplitudes are known a priori. The present study shows that the magnitude of the three-phase invariants can be determined with an uncertainty of ±10 degrees. The structure factor amplitudes of low-order beams are found with 5% accuracy.
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