The between-pass geometry walk kept a round only when the realised held-out residual fell by more
than its noise, and started only on a fit move of a trust-region step or more. The residual is
dominated by low-resolution reflections, where a distance and the compensating cell scale move every
spot alike, and its centroids are taken inside a disc centred on the prediction, so it barely sees a
distance error that costs the high-resolution shells. On 8pqd the canonical pass ran at 96.456 mm; the
fit asked for 95.878 mm (0.6 %, less than a step, so no walk). Forced, that round read the residual
only 0.74 sigma lower but put 70.4 % of the validation spots on the lattice against 58.1 %.
Now a round is kept when either the residual falls beyond its noise (HeldOutResidualFell) or the
validation evidence prefers it (ValidationEvidencePrefers, z = 3.29). A move of less than a step is
first tried as two index-only probes on the validation frames (fit's geometry vs the one in hand) and
pays for a re-integrated round only where the fit's geometry scores higher; walks started by a large
move run as before.
8pqd: 96.456 -> 95.878 mm, d_min 1.374 -> 1.306 A, R_free .218 -> .206, REFMAC R_free .209 -> .202,
Wilson B 34.4 -> 30.7 (pool had 1.325 A / .209 / .203). 6vww 7n0i 7ris 8egn 8xtf 9qw8 9w3y 6qaj
6cdl 9i0a myob_x06da_split lyso_x06da_half_image unchanged (probes say the geometry in hand stands);
probe cost 1-10 s per run.
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01D1G8gJVAy6gp1K5Dz3NE5C
leonarski_fandClaude Opus 5.5
8153646716
