International Tables A 3.1.3.1 gives 100 / -110 / -1-13 for character 9;
the last element was -3. With a negative determinant the transform is
left-handed and the "conventional" rhombohedral cell is not hexagonal -
beta came out around 110-134 degrees instead of 90 and c was far too
long. Any R lattice tall enough to reduce to character 9 was affected,
and the downstream Trigonal->Hexagonal promotion then forced 90/90/120
onto that wrong cell.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
leonarski_fandClaude Opus 5
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