Character 40 carried a verbatim copy of character 35's matrix
(0-10 / -100 / 00-1), whose determinant is 1. A C-centred conventional
cell needs determinant 2, so a genuine oC lattice was returned as its
primitive monoclinic cell while still being labelled Orthorhombic 'C':
the refiner then clamped a ~117 degree beta to 90 and prediction dropped
half the reflections of a cell that has no centring.
International Tables A 3.1.3.1 gives 0-10 / 012 / -100 for character 40.
Character 35 is correct as it stands and is left alone.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
leonarski_fandClaude Opus 5
4a8a8e69bf