The per-frame scale was fitted on the partials from 50 rocking events per
frame and taken from the fulls alone below. The counts of small-molecule
sweeps (3-43) and proteins (5-900) overlap, and a weak protein at 36
events per frame scaled from its fulls had no resolved error model at all
(ISa undetermined, d_min 5.10 A) where its partials gave ISa 32 and 4.88 A.
The first merge of a pass that is not a space-group search is now made
both ways, and the count stands as the prior unless its merge has no
resolved error model while the other merge has one. Search merges (P1 /
subgroups) take the prior.
The two ISa values are deliberately not compared beyond that. Tried as
the arbiter, "higher ISa wins" (and weighted R_meas as fallback) agreed
with the external yardsticks on 10 of 11 crystals but chose the partials
on a 6-events-per-frame small-molecule sweep: ISa 10.5 vs 8.7, weighted
R_meas 0.102 vs 0.115, SHELXL R1 0.105 vs 0.062 - the partiality error
the partial scale absorbs is shared by symmetry mates at the same
rocking geometry, so their agreement cannot see it. Statistics of the
difference between the two arms' frame scales did not separate that
sweep from the proteins that want the partials either.
Effect: only crystals whose prior arm fails change; every small-molecule
set and every protein control keeps its arm. Private weak protein: ISa
undetermined -> 32.3, d_min 5.10 -> 4.88 A, weighted R_meas .343 -> .337.
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01K5K8jvPPbmCrbqnWkddTuB
leonarski_fandClaude Opus 5.5
b126b9fc15
