Dynamical diffraction in a D-alanine crystal, giving rise to asymmetric intensity profiles in MD cases (top panel). X-rays of 10 keV, σ polarization. Inset: D-alanine zwitterion. Graphical indexing through Bragg-cone lines (bottom panel) provides a general picture of the nearby cases, their relative strength (line thickness) and the easy distinction of the out–in/in–out geometries (blue/red lines). MD peaks are seen at the intersections of Bragg-cone lines with the one (horizontal dashed line).