SpaceGroup.cpp

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// Mantid Repository : https://github.com/mantidproject/mantid
//
// Copyright © 2018 ISIS Rutherford Appleton Laboratory UKRI,
//   NScD Oak Ridge National Laboratory, European Spallation Source,
//   Institut Laue - Langevin & CSNS, Institute of High Energy Physics, CAS
// SPDX - License - Identifier: GPL - 3.0 +
#include "MantidGeometry/Crystal/SpaceGroup.h"
#include "MantidGeometry/Crystal/PointGroupFactory.h"
#include <algorithm>
#include <utility>
 
namespace Mantid::Geometry {
 
using namespace Kernel;
 
SpaceGroup::SpaceGroup(size_t itNumber, std::string hmSymbol, const Group &group)
    : Group(group), m_number(itNumber), m_hmSymbol(std::move(hmSymbol)) {}
 
size_t SpaceGroup::number() const { return m_number; }
 
std::string SpaceGroup::hmSymbol() const { return m_hmSymbol; }
 
bool SpaceGroup::isAllowedReflection(const Kernel::V3D &hkl) const {
  for (const auto &operation : m_allOperations) {
    if (operation.hasTranslation()) {
      /* Floating point precision problem:
       *    (H . v) % 1.0 is not always exactly 0, so instead:
       *    | [(H . v) + delta] % 1.0 | > 1e-14 is checked
       * The transformation is only performed if necessary.
       */
      if ((fabs(fmod(fabs(hkl.scalar_prod(operation.reducedVector())) + 1e-15, 1.0)) > 1e-14) &&
          (operation.transformHKL(hkl) == hkl)) {
        return false;
      }
    }
  }
 
  return true;
}
 
bool SpaceGroup::isAllowedUnitCell(const UnitCell &cell) const { return isInvariant(cell.getG()); }
 
PointGroup_sptr SpaceGroup::getPointGroup() const {
  return PointGroupFactory::Instance().createPointGroupFromSpaceGroup(*this);
}
 
Group_const_sptr SpaceGroup::getSiteSymmetryGroup(const V3D &position) const {
  V3D wrappedPosition = Geometry::getWrappedVector(position);
 
  std::vector<SymmetryOperation> siteSymmetryOps;
  AtomPositionsEqual comparator;
  std::copy_if(
      m_allOperations.begin(), m_allOperations.end(), std::inserter(siteSymmetryOps, siteSymmetryOps.begin()),
      [&](const SymmetryOperation &op) { return Geometry::getWrappedVector(op * wrappedPosition) == wrappedPosition; });
 
  return GroupFactory::create<Group>(siteSymmetryOps);
}
 
std::ostream &operator<<(std::ostream &stream, const SpaceGroup &self) {
  stream << "Space group with Hermann-Mauguin symbol: " << self.hmSymbol();
  return stream;
}
 
} // namespace Mantid::Geometry