The pre-draw guard keeps a null replicate from STARTING within RigidBodyReachDeg of an orientation
equivalent to the model's (space-group rotations x {identity + twin laws}), but the analytic-Jacobian
rigid body walks further than that reach: on 9yzk one replicate drawn outside the 10.6 deg reach was
walked 23.9 deg onto an equivalent orientation (R-free 0.5578 -> 0.3917), the null SD went
0.016 -> 0.066 and MODEL_FIT flipped ACCEPTED -> REJECTED.
Now where the replicate ENDS is checked too: RefineRigidBody reports the rotation it applied, the
final orientation is that times the drawn one, and a replicate that ended within reach is drawn again
(through the same pre-draw filter) and placed again, capped at NULL_MAX_REDRAWS. The redraws come from
a generator per replicate (NULL_SEED + 1 + i), so they do not depend on the order the concurrent
replicates finish in; the count is logged once per run. The real fit's procedure is unchanged.
Validation, 12 open-arm sets against 20260928-0459_24ae26_r6-pooled: post-placement redraws on 9yzk (1)
and 5epe (1), none elsewhere. 9yzk back to ACCEPTED, +14.15 sigma, null 0.5880 +- 0.0138 (base +12.21,
0.5864 +- 0.0158), p.mtz byte-identical to base. 5epe: MODEL_FIT +41.62 -> +46.39, indexing margin
+40.94 -> +31.97 sigma, same decision. Every other set identical to the previous rigid-bc commit.
-N 1 and the default thread count give identical outputs and logs on 9yzk and 6toc.
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01D1G8gJVAy6gp1K5Dz3NE5C