A stills merge no longer reports ISA. On stills 1/b is the I/sigma ceiling of a single still
observation under the stills model - the same frames processed as a rotation sweep read several
times higher - so it describes the processing model more than the instrument and the crystal, and
read on CORRECT.LP's scale it calls good serial data useless. The report gives the error model as
ERROR_MODEL_A, ERROR_MODEL_B (XDS convention, as before) and a new ERROR_MODEL_C, the partiality
term, in the same convention: sigma^2 = a*(sigma0^2 + b*I^2 + c*((1-p)/p)^2*I^2).
ERROR_MODEL_B= undetermined where b is zero within its error (ISA= said it before).
The same on every other place that showed the stills ISa: the summary's Signal row, the mmCIF
(_reflns.jfjoch_error_model_c instead of _reflns.jfjoch_diffrn_ISa), the log line, the live status
the broker serves, and the viewer's merge-statistics window (no ISa card and no ISa diagnostic for
a stills merge). MergeStatistics::stills marks a merge made by the stills path. The 1/b the
space-group search reads (merge_isa) is unchanged. Rotation output is unchanged.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01HVeDQqN9qRD57vnShzTC37
leonarski_fandClaude Opus 5.5
3caa11caa4