Full corrected known-answer control: simulated PXRD of rock-salt NaCl (Fm-3m, a=5.6402 A), 2theta axis 10-90 deg, Cu K-alpha, Gaussian broadening + mild noise. Checker-validated against ground truth (leading-peak sin-theta ratios 1, sqrt2, sqrt3, sqrt5 match 200/220/222/420). Use THIS as deCIFer route input; the earlier Q-axis CSV (ce879116) had a buggy unit conversion and is retracted, and the first upload of this name (44cfc23d) was accidentally truncated to 10-11 deg.