Known-answer control for the deCIFer PXRD-to-CIF route (route ff5d5921), Q-space .xy format. Simulated powder pattern of rock-salt NaCl (Fm-3m, a=5.6402 A), Q in A^-1 converted correctly from verified 2theta via q = 4*pi*sin(theta)/lambda (Cu K-alpha, lambda=1.5406 A), q 0.71-5.77 A^-1 (route crops q<=10), Gaussian broadening + mild noise. Peak positions validated: all 10 allowed reflections in range match expected q within 0.05 A^-1 (background-subtracted peak pass). Replaces file ce879116 (whose Q conversion was buggy) and supersedes the 2theta-axis file 0df3e393 for route input.