SymTools.cc

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#include "casm/crystallography/SymTools.hh"
 
#include <iterator>
#include <memory>
 
#include "casm/crystallography/Coordinate.hh"
#include "casm/crystallography/Lattice.hh"
#include "casm/crystallography/Structure.hh"
#include "casm/crystallography/UnitCellCoord.hh"
#include "casm/misc/CASM_Eigen_math.hh"
#include "casm/symmetry/SymBasisPermute.hh"
#include "casm/symmetry/SymGroup.hh"
#include "casm/symmetry/SymOp.hh"
#include "casm/symmetry/SymTools.hh"
#include "casm/symmetry/SymTools_impl.hh"
 
namespace {
CASM::SymGroup subgroup_from_indices(
    const CASM::SymGroup &super_group,
    const std::vector<CASM::Index> &subgroup_indices) {
  std::vector<CASM::SymOp> subgroup_operations;
  for (auto ix : subgroup_indices) {
    subgroup_operations.push_back(super_group[ix]);
  }
 
  return CASM::SymGroup(subgroup_operations, &(super_group.lattice()),
                        super_group.periodicity());
}
 
//*******************************************************************************************
}  // namespace
namespace CASM {
namespace sym {
SymGroup invariant_subgroup(const SymGroup &super_group,
                            const xtal::Lattice &lat) {
  auto subgroup_operation_indices =
      xtal::invariant_subgroup_indices(lat, super_group);
  return subgroup_from_indices(super_group, subgroup_operation_indices);
}
 
template <>
xtal::UnitCellCoord
copy_apply<CASM::SymOp, xtal::UnitCellCoord, xtal::Lattice, SymGroupRepID>(
    const CASM::SymOp &op, xtal::UnitCellCoord copied_ucc,
    const xtal::Lattice &prim_lattice, const SymGroupRepID &prim_symrep_ID) {
  // transform using stored SymBasisPermute representation
  const SymBasisPermute &rep = *op.get_basis_permute_rep(prim_symrep_ID);
  xtal::UnitCell new_unitcell = rep.matrix() * copied_ucc.unitcell() +
                                rep[copied_ucc.sublattice()].unitcell();
  auto new_sublattice = rep[copied_ucc.sublattice()].sublattice();
 
  // additional translations (such as needed for supercell factor groups),
  // are stored in SymOp::integral_tau() (in cartesian coordinates)
  // this converts that to fractional coordinates and adds it to the unitcell()
  new_unitcell += lround(prim_lattice.inv_lat_column_mat() * op.integral_tau());
 
  return xtal::UnitCellCoord(new_sublattice, new_unitcell);
}
 
template <>
xtal::UnitCellCoord &apply<CASM::SymOp, xtal::UnitCellCoord, xtal::Lattice,
                           SymGroupRepID>(const CASM::SymOp &op,
                                          xtal::UnitCellCoord &mutating_ucc,
                                          const xtal::Lattice &prim_lattice,
                                          const SymGroupRepID &prim_symrep_ID) {
  auto ucc_after_apply =
      copy_apply(op, mutating_ucc, prim_lattice, prim_symrep_ID);
  std::swap(ucc_after_apply, mutating_ucc);
  return mutating_ucc;
}
 
template <>
xtal::UnitCellCoord copy_apply<CASM::SymOp, xtal::UnitCellCoord, Structure>(
    const CASM::SymOp &op, xtal::UnitCellCoord copied_ucc,
    const Structure &prim) {
  sym::apply(op, copied_ucc, prim.lattice(),
             prim.basis_permutation_symrep_ID());
  return copied_ucc;
}
 
template <>
xtal::UnitCellCoord &apply<CASM::SymOp, xtal::UnitCellCoord, Structure>(
    const CASM::SymOp &op, xtal::UnitCellCoord &mutating_ucc,
    const Structure &prim) {
  sym::apply(op, mutating_ucc, prim.lattice(),
             prim.basis_permutation_symrep_ID());
  return mutating_ucc;
}
 
//*******************************************
template <>
xtal::Coordinate &apply<CASM::SymOp, xtal::Coordinate>(
    const CASM::SymOp &op, xtal::Coordinate &mutating_coord) {
  return mutating_coord;
}
 
}  // namespace sym
}  // namespace CASM