The fit was refused outright if it wanted to move the detector distance or a cell
edge by one per cent or more. The bound exists to stop a runaway, but it was
applied to the whole move rather than to a step, so a geometry that was genuinely
several per cent out could never be reached - on one dataset the refused fit was
310.000 -> 305.692 mm with a cell within 0.06 per cent of the deposited one, and it
was thrown away for being too large a correction.
A move of one per cent or more is now re-fitted as a walk of one per cent steps,
each seeded where the last arrived and each required to lower the held-out
split-half residual, and a walk of more than one step is ratified by re-indexing
at where it arrived. That is what the bound was really for: a second lattice does
not index better at the new geometry, and a real distance error does - on the
dataset this was found with, pass-1 frames go 37/60 to 60/60, R_meas 0.74 to
0.081, ISa 0.98 to 15.0, and the walk stops at a minimum bracketed on both sides
without ever being told what the answer should be. A walk that uses every step it
is allowed has not settled and is refused; that test is what stops the runaway
this replaces the veto with.
The first solve is untouched. An earlier version that also widened its box was
measurably not inert - two microns on one control moved a 694-reflection merge by
three points of R_meas - so a move inside the bound still commits exactly as before.
Refusals now say so in the report rather than passing silently. Four of ninety-nine
open datasets carry a uniform cell-scale error; ninety-eight of a hundred and three
are byte-identical or differ only by the new line, and no run on forty-eight
datasets with calibrated headers moves at all.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_011GxZqDiFP3KqriBhNdcR56
leonarski_fandClaude Opus 5
5d643498c6