Direct measurements of Bragg-reflection phases in x-ray crystallography

Abstract

We present a reference-beam x-ray-diffraction technique applied to a good-quality protein crystal. The technique is based on a multiple-beam diffraction principle and employs a modified oscillation camera in a Bragg inclined geometry, which allows a simultaneous measurement of both magnitudes and triplet phases of a large number of Bragg reflections from the sample. This work demonstrates that the reference-beam method can be a simple practical solution to the phase problem in x-ray crystallography.