From 4a8a8e69bf0f9f95c29e92073676ae5837ff9ebd Mon Sep 17 00:00:00 2001 From: Filip Leonarski Date: Fri, 31 Jul 2026 14:41:46 +0200 Subject: [PATCH] lattice_search: give Niggli character 40 its own reindex matrix 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) --- image_analysis/lattice_search/LatticeSearch.cpp | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/image_analysis/lattice_search/LatticeSearch.cpp b/image_analysis/lattice_search/LatticeSearch.cpp index a9f29e40..1f3ae4f7 100644 --- a/image_analysis/lattice_search/LatticeSearch.cpp +++ b/image_analysis/lattice_search/LatticeSearch.cpp @@ -238,7 +238,7 @@ LatticeSearchResult LatticeSearch(const CrystalLattice &L, double dist_tolerance { 40, 2, false, false, -B / 2, 0, 0, false, false, - {0, -1, 0, -1, 0, 0, 0, 0, -1}, + {0, -1, 0, 0, 1, 2, -1, 0, 0}, gemmi::CrystalSystem::Orthorhombic, 'C' }, {