Doubled-cell hypothesis: the run now always merges the doubled cell under <prefix>_doubled first and
decides with both merges in hand. Adopted only where (1) the probe's class grows significantly with
resolution (three standard errors between the 20-8 A shell and the finest measured one) and (2) in
the doubled merge one pseudo-translation - half a cell plus eps, fitted over the class - modulates at
least half of the added class in every shell (FitDoubledClassTranslation: A sin^2(pi h.eps) + B per
shell, share 1 - B/mean). Where adopted, every <prefix>_doubled file takes the plain name and the
probed cell's file of that name moves to <prefix>_halfcell. Replaces the HALF_CELL_BREAKS_DOWN bound.
Measured on the forced doubled merges: modulated share per shell 0.80-1.0 out to 1.9 A on the crystal
deposited in the doubled cell; on the ones deposited in the half cell it falls to 0.01-0.34 by
2.1-2.8 A (the rising class with twinning), or stays at -0.3-0.48 at every resolution (three others);
the one class it fully explains does not rise (eps 0.1 of a cell, flat at 0.1 of the lattice).
Space-group search: the trim of a screw zone's largest absence exempted a violation "at its row's
mean" on the de-modulated intensity, so under a deep pseudo-translation a reflection at 0.015 of its
row (de-modulated by 1/0.002) could never be trimmed and alone decided the row against the screw.
The exemption now reads the measured intensity, at both sites.
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01EizBKhTqrAYago9KJG3dA3
leonarski_fandClaude Opus 5.5
48201d35ec