Section 1.1 called (x_beam, y_beam) the direct-beam position while constructing
it as the point of normal incidence; on a tilted detector the two differ by
D*tan(tilt), and a reader loading a header direct beam into it would be wrong by
several pixels. Name it as the PONI (the system-wide convention,
DETECTOR_GEOMETRY.md), say which point the construction pins, and state the
laboratory frame's axes and handedness, which the rotation-sign, R-centring and
Bijvoet-hand discussions all silently depended on. Two-theta is computed as a
two-argument arctangent; say so.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01EFEJG6WBQv8th4UJFNe53N
leonarski_fandClaude Opus 5
694e687fce
