Two defects in the Bravais character walk, both of which silently cost symmetry. An impossible character MATCHED. The walk computes acos(cond_F/sqrt(A*B)); when the character is geometrically impossible the argument leaves [-1,1], acos returns NaN, and the acceptance test fabs(NaN - actual) > tol is FALSE - so the character is taken. One corpus crystal matched a monoclinic-C character whose implied cos(gamma) is 1.086. The type-boundary retry covered beta only. All three angles carry the Niggli boundary, and negating two basis vectors supplements the OTHER two, so each angle needs its own flip. A crystal whose reduced gamma sits at 89.900 degrees needs the alpha/beta flip and never got it. Measured on 84369 exact lattices spanning all 14 Bravais classes: nothing is lost in any class, and orthorhombic-I recovery rises from 60.3% to 87.2%. Over 440000 random and perturbed cells the first change only ever demotes a monoclinic-C match to triclinic and the second only ever promotes out of triclinic - it is a strict superset of the beta-only retry. On the 94-dataset corpus, two crystals gain their correct point group and none regresses. Both regression tests fail without the change. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01Lc5JG6kJqZoCWaoZ43JGTW
547 lines
20 KiB
C++
547 lines
20 KiB
C++
// SPDX-FileCopyrightText: 2025 Filip Leonarski, Paul Scherrer Institute <filip.leonarski@psi.ch>
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// SPDX-License-Identifier: GPL-3.0-only
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#include <catch2/catch_all.hpp>
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#include "../common/CrystalLattice.h"
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#include "../common/Coord.h"
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#include "../common/UnitCell.h"
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#include "../image_analysis/lattice_search/LatticeSearch.h"
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#include "gemmi/symmetry.hpp"
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#include <cmath>
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// Helper: check near-equality of unit cell parameters
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static void check_uc(const UnitCell& uc, double a, double b, double c,
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double alpha, double beta, double gamma,
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double eps_len = 1e-6, double eps_ang = 1e-4) {
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CHECK(uc.a == Catch::Approx(a).margin(eps_len));
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CHECK(uc.b == Catch::Approx(b).margin(eps_len));
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CHECK(uc.c == Catch::Approx(c).margin(eps_len));
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CHECK(uc.alpha == Catch::Approx(alpha).margin(eps_ang));
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CHECK(uc.beta == Catch::Approx(beta ).margin(eps_ang));
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CHECK(uc.gamma == Catch::Approx(gamma).margin(eps_ang));
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}
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TEST_CASE("LatticeSearch - cubic I") {
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// Build a body-centered cubic cell with a=40:
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// primitive basis vectors (conventional I cubic primitive):
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// p1 = (0, a/2, a/2), p2 = (a/2, 0, a/2), p3 = (a/2, a/2, 0)
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const double a = 40.0;
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CrystalLattice L(
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Coord(a, 0, 0),
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Coord(0, a, 0),
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Coord(0, 0, a)
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);
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L = L.ToPrimitive('I');
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auto res = LatticeSearch(L, 1e-6);
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CHECK(res.system == gemmi::CrystalSystem::Cubic);
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CHECK(res.centering == 'I');
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// Conventional cubic I should have equal edges and 90° angles
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auto uc = res.conventional.GetUnitCell();
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CHECK(uc.a == Catch::Approx( a )); // In this construction, conventional a matches given a
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CHECK(uc.b == Catch::Approx( a ));
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CHECK(uc.c == Catch::Approx( a ));
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CHECK(uc.alpha == Catch::Approx(90.0));
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CHECK(uc.beta == Catch::Approx(90.0));
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CHECK(uc.gamma == Catch::Approx(90.0));
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}
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TEST_CASE("LatticeSearch - cubic F") {
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// Build a body-centered cubic cell with a=40:
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// primitive basis vectors (conventional I cubic primitive):
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// p1 = (0, a/2, a/2), p2 = (a/2, 0, a/2), p3 = (a/2, a/2, 0)
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const double a = 40.0;
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CrystalLattice L(
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Coord(a, 0, 0),
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Coord(0, a, 0),
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Coord(0, 0, a)
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);
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L = L.ToPrimitive('F');
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auto res = LatticeSearch(L, 1e-6);
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CHECK(res.system == gemmi::CrystalSystem::Cubic);
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CHECK(res.centering == 'F');
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// Conventional cubic I should have equal edges and 90° angles
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auto uc = res.conventional.GetUnitCell();
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CHECK(uc.a == Catch::Approx( a )); // In this construction, conventional a matches given a
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CHECK(uc.b == Catch::Approx( a ));
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CHECK(uc.c == Catch::Approx( a ));
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CHECK(uc.alpha == Catch::Approx(90.0));
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CHECK(uc.beta == Catch::Approx(90.0));
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CHECK(uc.gamma == Catch::Approx(90.0));
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}
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TEST_CASE("LatticeSearch - cubic P") {
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// Simple cubic P, a=30
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const double a = 30.0;
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CrystalLattice L(
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Coord(a,0,0),
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Coord(0,a,0),
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Coord(0,0,a)
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);
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auto res = LatticeSearch(L, 1e-6);
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CHECK(res.system == gemmi::CrystalSystem::Cubic);
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CHECK(res.centering == 'P');
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auto uc = res.conventional.GetUnitCell();
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check_uc(uc, a, a, a, 90.0, 90.0, 90.0, 1e-6, 1e-4);
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}
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TEST_CASE("LatticeSearch - tetragonal I") {
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// Build a body-centered cubic cell with a=40:
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// primitive basis vectors (conventional I cubic primitive):
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// p1 = (0, a/2, a/2), p2 = (a/2, 0, a/2), p3 = (a/2, a/2, 0)
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const double a = 40.0;
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const double b = 34.0;
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CrystalLattice L(
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Coord(a, 0, 0),
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Coord(0, a, 0),
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Coord(0, 0, b)
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);
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L = L.ToPrimitive('I');
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auto res = LatticeSearch(L, 1e-6);
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CHECK(res.system == gemmi::CrystalSystem::Tetragonal);
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CHECK(res.centering == 'I');
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// Conventional cubic I should have equal edges and 90° angles
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auto uc = res.conventional.GetUnitCell();
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CHECK(uc.a == Catch::Approx( a )); // In this construction, conventional a matches given a
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CHECK(uc.b == Catch::Approx( a ));
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CHECK(uc.c == Catch::Approx( b ));
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CHECK(uc.alpha == Catch::Approx(90.0));
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CHECK(uc.beta == Catch::Approx(90.0));
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CHECK(uc.gamma == Catch::Approx(90.0));
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}
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TEST_CASE("LatticeSearch - tetragonal I - v2") {
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// Build a body-centered cubic cell with a=40:
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// primitive basis vectors (conventional I cubic primitive):
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// p1 = (0, a/2, a/2), p2 = (a/2, 0, a/2), p3 = (a/2, a/2, 0)
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const double a = 40.0;
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const double b = 54.0;
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CrystalLattice L(
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Coord(a, 0, 0),
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Coord(0, a, 0),
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Coord(0, 0, b)
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);
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L = L.ToPrimitive('I');
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auto res = LatticeSearch(L, 1e-6);
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CHECK(res.system == gemmi::CrystalSystem::Tetragonal);
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CHECK(res.centering == 'I');
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// Conventional cubic I should have equal edges and 90° angles
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auto uc = res.conventional.GetUnitCell();
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CHECK(uc.a == Catch::Approx( a )); // In this construction, conventional a matches given a
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CHECK(uc.b == Catch::Approx( a ));
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CHECK(uc.c == Catch::Approx( b ));
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CHECK(uc.alpha == Catch::Approx(90.0));
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CHECK(uc.beta == Catch::Approx(90.0));
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CHECK(uc.gamma == Catch::Approx(90.0));
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}
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// Tetragonal P: a=b!=c, all angles 90, P-centering
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TEST_CASE("LatticeSearch - tetragonal P") {
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const double a = 37.0, c = 59.0;
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CrystalLattice L(
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Coord(a,0,0),
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Coord(0,a,0),
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Coord(0,0,c)
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);
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auto res = LatticeSearch(L, 1e-6);
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CHECK(res.system == gemmi::CrystalSystem::Tetragonal);
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CHECK(res.centering == 'P');
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auto uc = res.conventional.GetUnitCell();
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check_uc(uc, a, a, c, 90.0, 90.0, 90.0, 1e-2, 1e-2);
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}
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// Orthorhombic F: all angles 90, unequal edges, F-centering
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TEST_CASE("LatticeSearch - orthorhombic F") {
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const double a = 35.0, b = 41.0, c = 57.0;
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CrystalLattice conv(a,b,c, 90.0,90.0,90.0);
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CrystalLattice L = conv.ToPrimitive('F');
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auto res = LatticeSearch(L, 1e-6);
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CHECK(res.system == gemmi::CrystalSystem::Orthorhombic);
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CHECK(res.centering == 'F');
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auto uc = res.conventional.GetUnitCell();
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check_uc(uc, a, b, c, 90.0, 90.0, 90.0, 1e-1, 1e-2);
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}
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TEST_CASE("LatticeSearch - orthorhombic F - permutation 1") {
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const double a = 41.0, b = 57.0, c = 35.0;
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CrystalLattice conv(a,b,c, 90.0,90.0,90.0);
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CrystalLattice L = conv.ToPrimitive('F');
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auto res = LatticeSearch(L, 1e-6);
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CHECK(res.system == gemmi::CrystalSystem::Orthorhombic);
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CHECK(res.centering == 'F');
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auto uc = res.conventional.GetUnitCell();
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check_uc(uc, c, a, b, 90.0, 90.0, 90.0, 1e-1, 1e-2);
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}
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// Orthorhombic C: all angles 90, unequal edges, C-centering
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TEST_CASE("LatticeSearch - orthorhombic C") {
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const double a = 35.0, b = 41.0, c = 57.0;
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CrystalLattice conv(a,b,c, 90.0,90.0,90.0);
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CrystalLattice L = conv.ToPrimitive('C');
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auto res = LatticeSearch(L, 1e-6);
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CHECK(res.system == gemmi::CrystalSystem::Orthorhombic);
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CHECK(res.centering == 'C');
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auto uc = res.conventional.GetUnitCell();
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check_uc(uc, a, b, c, 90.0, 90.0, 90.0, 1e-1, 1e-2);
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}
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TEST_CASE("LatticeSearch - orthorhombic I") {
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const double a = 35.0, b = 41.0, c = 57.0;
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CrystalLattice conv(a,b,c, 90.0,90.0,90.0);
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CrystalLattice L = conv.ToPrimitive('I');
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auto res = LatticeSearch(L, 1e-6);
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CHECK(res.system == gemmi::CrystalSystem::Orthorhombic);
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CHECK(res.centering == 'I');
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auto uc = res.conventional.GetUnitCell();
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check_uc(uc, a, b, c, 90.0, 90.0, 90.0, 1e-2, 1e-2);
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}
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TEST_CASE("LatticeSearch - orthorhombic I - permutation1") {
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const double a = 57.0, b = 41.0, c = 35.0;
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CrystalLattice conv(a,b,c, 90.0,90.0,90.0);
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CrystalLattice L = conv.ToPrimitive('I');
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auto res = LatticeSearch(L, 1e-6);
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CHECK(res.system == gemmi::CrystalSystem::Orthorhombic);
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CHECK(res.centering == 'I');
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auto uc = res.conventional.GetUnitCell();
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check_uc(uc, c, b, a, 90.0, 90.0, 90.0, 1e-2, 1e-2);
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}
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TEST_CASE("LatticeSearch - orthorhombic I - permutation2") {
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const double a = 41.0, b = 57.0, c = 35.0;
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CrystalLattice conv(a,b,c, 90.0,90.0,90.0);
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CrystalLattice L = conv.ToPrimitive('I');
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auto res = LatticeSearch(L, 1e-6);
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CHECK(res.system == gemmi::CrystalSystem::Orthorhombic);
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CHECK(res.centering == 'I');
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auto uc = res.conventional.GetUnitCell();
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check_uc(uc, c, a, b, 90.0, 90.0, 90.0, 1e-2, 1e-2);
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}
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// A character states its scalar products as fractions of A, B and C, and the three C-centred
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// monoclinic ones (28, 29, 30) state one of them as 2*D or 2*E - twice a cosine. The cosine that
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// implies leaves [-1,1] as soon as the cell's own angle is far enough from 90, and the character is
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// then geometrically impossible for that metric. This cell is triclinic; character 28 asks it for a
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// gamma whose cosine is 1.127.
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TEST_CASE("LatticeSearch - an impossible character is not a match") {
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CrystalLattice L(30.0, 35.0, 40.0, 65.0, 70.0, 70.0);
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auto res = LatticeSearch(L, 1e-6);
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CHECK(res.system == gemmi::CrystalSystem::Triclinic);
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}
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// An exact I-centred orthorhombic lattice whose reduced cell comes out all-acute with gamma at 90 -
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// ON the boundary between the two Niggli types, where the reduction may present either. Character 42
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// is stated for the obtuse setting, and only the flip that keeps gamma reaches it. Both defects have
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// to be gone: without the impossible-character fix this metric matches character 28 and never gets
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// as far as the retry, and without the gamma flip the retry does not have the setting it needs.
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TEST_CASE("LatticeSearch - orthorhombic I on the type boundary in gamma") {
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const double a = 45.0, b = 50.0, c = 80.0;
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CrystalLattice conv(a, b, c, 90.0, 90.0, 90.0);
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CrystalLattice L = conv.ToPrimitive('I');
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auto res = LatticeSearch(L, 1e-6);
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CHECK(res.system == gemmi::CrystalSystem::Orthorhombic);
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CHECK(res.centering == 'I');
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auto uc = res.conventional.GetUnitCell();
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check_uc(uc, a, b, c, 90.0, 90.0, 90.0, 1e-2, 1e-2);
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}
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// Orthorhombic P: all angles 90, unequal edges, P-centering
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TEST_CASE("LatticeSearch - orthorhombic P") {
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const double a = 35.0, b = 41.0, c = 57.0;
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CrystalLattice L(a,b,c, 90.0,90.0,90.0);
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auto res = LatticeSearch(L, 1e-6);
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CHECK(res.system == gemmi::CrystalSystem::Orthorhombic);
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CHECK(res.centering == 'P');
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auto uc = res.conventional.GetUnitCell();
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check_uc(uc, a, b, c, 90.0, 90.0, 90.0, 1e-6, 1e-4);
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}
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// Hexagonal P: a=b!=c, alpha=beta=90, gamma=120, P-centering
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TEST_CASE("LatticeSearch - hexagonal P") {
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const double a = 30.0, c = 48.0;
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CrystalLattice L(
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Coord(a, 0, 0),
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Coord(-a/2, a*std::sqrt(3)/2, 0),
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Coord(0, 0, c)
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);
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auto res = LatticeSearch(L, 1e-6);
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CHECK(res.system == gemmi::CrystalSystem::Hexagonal);
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CHECK(res.centering == 'P');
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auto uc = res.conventional.GetUnitCell();
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CHECK(uc.a == Catch::Approx(a).margin(1e-2));
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CHECK(uc.b == Catch::Approx(a).margin(1e-2));
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CHECK(uc.c == Catch::Approx(c).margin(1e-2));
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CHECK(uc.alpha == Catch::Approx(90.0).margin(1e-2));
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CHECK(uc.beta == Catch::Approx(90.0).margin(1e-2));
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CHECK(uc.gamma == Catch::Approx(120.0).margin(1e-2));
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}
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TEST_CASE("LatticeSearch - monoclinic C (unique b)") {
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const double a = 50.0, b = 60.0, c = 70.0;
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const double alpha = 90.0, beta = 96.0, gamma = 90.0;
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CrystalLattice conv(a,b,c, alpha,beta,gamma);
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auto L = conv.ToPrimitive('C');
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auto res = LatticeSearch(L, 1e-6);
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CHECK(res.system == gemmi::CrystalSystem::Monoclinic);
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CHECK(res.centering == 'C');
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auto uc = res.conventional.GetUnitCell();
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// Check right angles at alpha,gamma and non-90 beta; lengths comparable
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CHECK(std::fabs(uc.alpha - 90.0) < 1e-3);
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CHECK(std::fabs(uc.gamma - 90.0) < 1e-3);
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CHECK(std::fabs(uc.beta - beta) < 1e-2);
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// Lengths should match within small tolerance
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CHECK(uc.a == Catch::Approx(a).margin(1e-2));
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CHECK(uc.b == Catch::Approx(b).margin(1e-2));
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CHECK(uc.c == Catch::Approx(c).margin(1e-2));
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}
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TEST_CASE("LatticeSearch - monoclinic C (unique b) - v2") {
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const double a = 71.0, b = 35.0, c = 90.0;
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const double alpha = 90.0, beta = 96.0, gamma = 90.0;
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CrystalLattice conv(a,b,c, alpha,beta,gamma);
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auto L = conv.ToPrimitive('C');
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auto res = LatticeSearch(L, 1e-6);
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CHECK(res.system == gemmi::CrystalSystem::Monoclinic);
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CHECK(res.centering == 'C');
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auto uc = res.conventional.GetUnitCell();
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// Check right angles at alpha,gamma and non-90 beta; lengths comparable
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CHECK(std::fabs(uc.alpha - 90.0) < 1e-3);
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CHECK(std::fabs(uc.gamma - 90.0) < 1e-3);
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CHECK(std::fabs(uc.beta - beta) < 1e-2);
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// Lengths should match within small tolerance
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CHECK(uc.a == Catch::Approx(a).margin(1e-2));
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CHECK(uc.b == Catch::Approx(b).margin(1e-2));
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CHECK(uc.c == Catch::Approx(c).margin(1e-2));
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}
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TEST_CASE("LatticeSearch - monoclinic C (unique a)") {
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const double a = 60.0, b = 50.0, c = 70.0;
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const double alpha = 96.0, beta = 90.0, gamma = 90.0;
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CrystalLattice conv(a,b,c, alpha,beta,gamma);
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auto L = conv.ToPrimitive('C');
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auto res = LatticeSearch(L, 1e-6);
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CHECK(res.system == gemmi::CrystalSystem::Monoclinic);
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CHECK(res.centering == 'C');
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auto uc = res.conventional.GetUnitCell();
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// Check right angles at alpha,gamma and non-90 beta; lengths comparable
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CHECK(std::fabs(uc.alpha - 90.0) < 1e-3);
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CHECK(std::fabs(uc.gamma - 90.0) < 1e-3);
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CHECK(std::fabs(uc.beta - alpha) < 1e-2);
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// Lengths should match within small tolerance
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CHECK(uc.a == Catch::Approx(b).margin(1e-2));
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CHECK(uc.b == Catch::Approx(a).margin(1e-2));
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CHECK(uc.c == Catch::Approx(c).margin(1e-2));
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}
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TEST_CASE("LatticeSearch - monoclinic P (unique b)") {
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const double a = 50.0, b = 60.0, c = 70.0;
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const double alpha = 90.0, beta = 96.0, gamma = 90.0;
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CrystalLattice conv(a,b,c, alpha,beta,gamma);
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auto res = LatticeSearch(conv, 1e-6);
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CHECK(res.system == gemmi::CrystalSystem::Monoclinic);
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CHECK(res.centering == 'P');
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|
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auto uc = res.conventional.GetUnitCell();
|
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// Check right angles at alpha,gamma and non-90 beta; lengths comparable
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CHECK(std::fabs(uc.alpha - 90.0) < 1e-3);
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CHECK(std::fabs(uc.gamma - 90.0) < 1e-3);
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CHECK(std::fabs(uc.beta - beta) < 1e-2);
|
|
// Lengths should match within small tolerance
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CHECK(uc.a == Catch::Approx(a).margin(1e-2));
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CHECK(uc.b == Catch::Approx(b).margin(1e-2));
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CHECK(uc.c == Catch::Approx(c).margin(1e-2));
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}
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|
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TEST_CASE("LatticeSearch - monoclinic P (unique b) - v2") {
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const double a = 90.0, b = 35.0, c = 71.0;
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const double alpha = 90.0, beta = 96.0, gamma = 90.0;
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CrystalLattice conv(a,b,c, alpha,beta,gamma);
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|
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auto res = LatticeSearch(conv, 1e-6);
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|
|
|
CHECK(res.system == gemmi::CrystalSystem::Monoclinic);
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|
CHECK(res.centering == 'P');
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|
|
|
auto uc = res.conventional.GetUnitCell();
|
|
// Check right angles at alpha,gamma and non-90 beta; lengths comparable
|
|
CHECK(std::fabs(uc.alpha - 90.0) < 1e-3);
|
|
CHECK(std::fabs(uc.gamma - 90.0) < 1e-3);
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|
CHECK(std::fabs(uc.beta - beta) < 1e-2);
|
|
// Lengths should match within small tolerance
|
|
CHECK(uc.a == Catch::Approx(c).margin(1e-2));
|
|
CHECK(uc.b == Catch::Approx(b).margin(1e-2));
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|
CHECK(uc.c == Catch::Approx(a).margin(1e-2));
|
|
}
|
|
|
|
TEST_CASE("LatticeSearch - triclinic P") {
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// General triclinic primitive cell
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CrystalLattice L(33.1, 41.7, 52.3, 89.1, 85.0, 76.3);
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|
|
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auto res = LatticeSearch(L, 1e-6);
|
|
|
|
// System should be triclinic, centering P, and conventional equals some standardized primitive
|
|
CHECK(res.system == gemmi::CrystalSystem::Triclinic);
|
|
CHECK(res.centering == 'P');
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|
|
|
// The conventional cell should be metric-equivalent to input. We verify only the system and centering here.
|
|
// Reduced primitive must be non-singular
|
|
auto uc_red = res.primitive_reduced.GetUnitCell();
|
|
CHECK(uc_red.a > 0);
|
|
CHECK(uc_red.b > 0);
|
|
CHECK(uc_red.c > 0);
|
|
}
|
|
|
|
TEST_CASE("LatticeSearch - triclinic P - v2") {
|
|
// General triclinic primitive cell
|
|
CrystalLattice L(33.1, 41.7, 52.3, 100, 92, 115);
|
|
|
|
auto res = LatticeSearch(L, 1e-6);
|
|
|
|
// System should be triclinic, centering P, and conventional equals some standardized primitive
|
|
CHECK(res.system == gemmi::CrystalSystem::Triclinic);
|
|
CHECK(res.centering == 'P');
|
|
|
|
// The conventional cell should be metric-equivalent to input. We verify only the system and centering here.
|
|
// Reduced primitive must be non-singular
|
|
auto uc_red = res.primitive_reduced.GetUnitCell();
|
|
CHECK(uc_red.a > 0);
|
|
CHECK(uc_red.b > 0);
|
|
CHECK(uc_red.c > 0);
|
|
}
|
|
|
|
TEST_CASE("LatticeSearch - trigonal R") {
|
|
const double a = 32.0;
|
|
const double alpha = 80.0;
|
|
|
|
// Build rhombohedral in rhombohedral setting (primitive axes a=b=c, alpha=beta=gamma)
|
|
CrystalLattice L(a, a, a, alpha, alpha, alpha);
|
|
|
|
auto res = LatticeSearch(L, 1e-6);
|
|
|
|
CHECK(res.system == gemmi::CrystalSystem::Trigonal);
|
|
CHECK(res.centering == 'R');
|
|
|
|
auto uc_red = res.conventional.GetUnitCell();
|
|
CHECK(uc_red.alpha == Catch::Approx(90).margin(1e-2));
|
|
CHECK(uc_red.beta == Catch::Approx(90).margin(1e-2));
|
|
CHECK(uc_red.gamma == Catch::Approx(120).margin(1e-2));
|
|
|
|
auto uc_prim = res.primitive_reduced.GetUnitCell();
|
|
CHECK(uc_prim.alpha == Catch::Approx(alpha).margin(1e-2));
|
|
CHECK(uc_prim.beta == Catch::Approx(alpha).margin(1e-2));
|
|
CHECK(uc_prim.gamma == Catch::Approx(alpha).margin(1e-2));
|
|
}
|
|
|
|
// The class-filtered walk: the same table, restricted to one Bravais class. A tetragonal-P lattice is
|
|
// also a C-centred orthorhombic one (a_C = a+b, b_C = -a+b, c_C = c), and asking for that class has to
|
|
// return that setting even though the plain search rightly prefers the tetragonal one.
|
|
TEST_CASE("LatticeSearchForClass - tetragonal P also has a C-centred orthorhombic setting") {
|
|
const double a = 50.0, c = 120.0;
|
|
const CrystalLattice L(a, a, c, 90, 90, 90);
|
|
|
|
const auto plain = LatticeSearch(L, 1e-6);
|
|
CHECK(plain.system == gemmi::CrystalSystem::Tetragonal);
|
|
CHECK(plain.centering == 'P');
|
|
|
|
const auto ortho = LatticeSearchForClass(L, gemmi::CrystalSystem::Orthorhombic, 'C', 1e-6);
|
|
REQUIRE(ortho.has_value());
|
|
CHECK(ortho->system == gemmi::CrystalSystem::Orthorhombic);
|
|
CHECK(ortho->centering == 'C');
|
|
const auto uc = ortho->conventional.GetUnitCell();
|
|
// The C cell is the face diagonal on a and b, so twice the volume and a = b = a_tet * sqrt(2).
|
|
CHECK(uc.a == Catch::Approx(a * std::sqrt(2.0)).margin(1e-4));
|
|
CHECK(uc.b == Catch::Approx(a * std::sqrt(2.0)).margin(1e-4));
|
|
CHECK(uc.c == Catch::Approx(c).margin(1e-4));
|
|
CHECK(uc.alpha == Catch::Approx(90).margin(1e-4));
|
|
CHECK(uc.beta == Catch::Approx(90).margin(1e-4));
|
|
CHECK(uc.gamma == Catch::Approx(90).margin(1e-4));
|
|
}
|
|
|
|
TEST_CASE("LatticeSearchForClass - a class the metric cannot carry is refused") {
|
|
// A general triclinic metric has no monoclinic-C setting, and an F-centred cubic lattice has no
|
|
// hexagonal-P one (its hexagonal description is R-centred).
|
|
const CrystalLattice tri(41.0, 47.0, 53.0, 71.0, 83.0, 97.0);
|
|
CHECK_FALSE(LatticeSearchForClass(tri, gemmi::CrystalSystem::Monoclinic, 'C').has_value());
|
|
|
|
const double a = 60.0;
|
|
const auto cubic_f = CrystalLattice(a, a, a, 90, 90, 90).ToPrimitive('F');
|
|
CHECK(LatticeSearch(cubic_f, 1e-6).centering == 'F');
|
|
CHECK_FALSE(LatticeSearchForClass(cubic_f, gemmi::CrystalSystem::Hexagonal, 'P').has_value());
|
|
// ... but its rhombohedral setting is there, which is what makes the refusal above a real answer
|
|
// rather than an artefact of the filter.
|
|
const auto rhomb = LatticeSearchForClass(cubic_f, gemmi::CrystalSystem::Trigonal, 'R');
|
|
REQUIRE(rhomb.has_value());
|
|
CHECK(rhomb->centering == 'R');
|
|
}
|
|
|
|
TEST_CASE("LatticeSearchForClass - asking for what the plain search found returns the same setting") {
|
|
const double a = 40.0;
|
|
const auto L = CrystalLattice(a, a, a, 90, 90, 90).ToPrimitive('I');
|
|
const auto plain = LatticeSearch(L, 1e-6);
|
|
const auto filtered = LatticeSearchForClass(L, plain.system, plain.centering, 1e-6);
|
|
REQUIRE(filtered.has_value());
|
|
CHECK(filtered->niggli_class == plain.niggli_class);
|
|
check_uc(filtered->conventional.GetUnitCell(), a, a, a, 90, 90, 90, 1e-4, 1e-4);
|
|
}
|