2 Commits

Include renames

Author	SHA1	Message	Date
leonarski_fandClaude Opus 5	6773e8516d	symmetry: a metric two-fold the lattice search refused is asked of the intensities ... The Niggli character walk takes the first character its tolerance matches, and on a lattice that is nearly but not exactly hexagonal it matches hexagonal. Under a hexagonal holohedry no candidate point group can carry the two strongest two-folds the data actually have, so the search lands on the weakest one and the crystal is processed in a group of order two where it should have been eight. The metric group knows better than the character walk: it holds every rotation the cell can host, including the ones the named lattice system has no room for. Each of those is now put to the intensities directly - one operator, scored the way Stage A scores its own, on the same reflection population, with the same strong-reflection gate and the same E^2 cap. That last part is what makes the answer usable: normalising over the full resolution range of a merge whose outer shells are correlated junk reads a genuine two-fold at CC 0.05, and the same operator over the population the pipeline itself pairs reads 0.88. The flattening and normalising the search does at its start is now one function, so an operator can be asked about without enumerating a point group around it. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01EFEJG6WBQv8th4UJFNe53N	2026-09-06 07:21:41 +02:00
leonarski_fandClaude Opus 5	491167c90d	rugnux: a Bravais class the reduction decided by rounding is re-asked on the metric's own cell ... The class is named by Niggli-reducing the indexed cell and looking the reduced cell up in the 44 lattice characters, and that lookup is a coin flip for any lattice whose Buerger cells straddle the Niggli type-I/type-II boundary. An F-centred cubic lattice does so by construction: it has reduced forms on both sides, the two sides carry different characters, and which side the reduction lands on is set by the last digits of whatever refinement produced the cell. Measured over 600 perturbations of one such lattice: 43% cubic F, 36% tetragonal I, 21% orthorhombic I, and the split is flat over a factor of ten in the noise. The class then caps the point-group search, so from the body-centred sub-cell the cubic three-fold is never enumerated and the run reports that nothing was refused - which is accurate, because nothing was asked. Le Page's two-fold search has no such key: it measures each rotation's obliquity on the lattice itself, in a primitive basis. LePageLattice turns the rotation group it finds into a conventional cell, a centring letter and an integral change of basis, and where that group is larger than the adopted class's holohedry the merge is reindexed into that cell and the space-group search is run again there, on both merges, with every gate live. Nothing here decides: the reindex is committed only where the search in the new setting confirms a strictly higher point group AND the centring the new cell describes, so a pseudo-symmetric metric leaves the answer already in hand standing. Measured as a paired battery over 113 rotation datasets: the re-ask fires on 7 and adopts on 1, and that one crystal - an F-centred cubic lattice the reduction had named body-centred tetragonal - moves to its deposited group, gaining 0.10 A of resolution and 2.8x the multiplicity at R_meas 0.117 -> 0.120. Nothing else moves, in space group, resolution, CC1/2, R_meas, multiplicity, I/sigma or completeness. A second such crystal, named body-centred orthorhombic, is offered the same cubic cell and confirms all 23 added operators at CC 0.96 with an H ratio of 1.00, and is still refused, on the merge chi^2 ratio at 2.50x a bound of 1.85. Letting H rescue that refusal is the one-line change an earlier round measured and rejected - it promotes the synthetic P 4_3 2_1 2 in the test suite to point group 432 - so it is not here, and that crystal is left where it was. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01EFEJG6WBQv8th4UJFNe53N	2026-09-03 13:53:14 +02:00