Improvement of accuracy and precision in refinement of crystal structure factors using zone-axis incidence and tilted CBED patters*

Crystal structure analysis method developed by Tsuda and Tanaka [1] has been applied for the refinement of isotropic atomic displacement parameters and structure factors of five low-order reflections of potassium tantalate (KTaO₃). Structure factors determined from zone-axis (ZA) incidences and tilted convergent-beam electron diffraction (CBED) patterns are compared. Discussions about precisions and sensitivities of the ZA incidences and the tilted CBED patterns for refinements of the structure factors is made. CBED patterns taken at tilted incidences showed higher precisions for determination of the structure factors than ZA incidences. The present analysis reveals different tendencies of sensitivities of the ZA incidence patterns and the tilted CBED patterns to changes of the structure factors of reflections, suggesting to use both of them for higher sensitivity and precision in refinements of the structure factors.
[1] Tsuda et al., Acta Cryst. A55, 939 (1999).