Program Listing for File bz_nest.hpp

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/* This file is part of brille.

Copyright © 2019,2020 Greg Tucker <greg.tucker@stfc.ac.uk>

brille is free software: you can redistribute it and/or modify it under the
terms of the GNU Affero General Public License as published by the Free
Software Foundation, either version 3 of the License, or (at your option)
any later version.

brille is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
or FITNESS FOR A PARTICULAR PURPOSE.
See the GNU Affero General Public License for more details.

You should have received a copy of the GNU Affero General Public License
along with brille. If not, see <https://www.gnu.org/licenses/>.            */
#ifndef BRILLE_BZ_NEST_
#define BRILLE_BZ_NEST_
#include <tuple>
#include "bz.hpp"
#include "nest.hpp"
namespace brille {

template<class T, class S>
class BrillouinZoneNest3: public Nest<T,S>{
  using SuperClass = Nest<T,S>;
  BrillouinZone brillouinzone;
public:
  template<typename... A>
  BrillouinZoneNest3(const BrillouinZone& bz, A... args):
    SuperClass(bz.get_ir_polyhedron(), args...),
    brillouinzone(bz) {}
  BrillouinZone get_brillouinzone(void) const {return this->brillouinzone;}
  bArray<double> get_xyz(void) const {return this->vertices();}
  const bArray<double>& get_all_xyz(void) const {return this->all_vertices(); }
  bArray<double> get_hkl(void) const { return xyz_to_hkl(brillouinzone.get_lattice(),this->vertices());}
  bArray<double> get_all_hkl(void) const {return xyz_to_hkl(brillouinzone.get_lattice(),this->all_vertices()); }
  // //! get the indices forming the faces of the tetrahedra
  // std::vector<std::array<size_t,4>> get_vertices_per_tetrahedron(void) const {return this->tetrahedra();}

  template<class R>
  std::tuple<brille::Array<T>,brille::Array<S>>
  ir_interpolate_at(const LQVec<R>& x, const int nth, const bool no_move=false) const {
    LQVec<R> ir_q(x.get_lattice(), x.size(0));
    LQVec<int> tau(x.get_lattice(), x.size(0));
    std::vector<size_t> rot(x.size(0),0u), invrot(x.size(0),0u);
    if (no_move){
      ir_q = x;
    } else if (!brillouinzone.ir_moveinto(x, ir_q, tau, rot, invrot, nth)){
      std::string msg;
      msg = "Moving all points into the irreducible Brillouin zone failed.";
      throw std::runtime_error(msg);
    }
    auto ir_q_invA = ir_q.get_xyz();
    // perform the interpolation within the irreducible Brillouin zone
    auto [vals, vecs] = (nth > 1)
        ? this->SuperClass::interpolate_at(ir_q_invA, nth)
        : this->SuperClass::interpolate_at(ir_q_invA);
    // we always need the pointgroup operations to 'rotate'
    PointSymmetry psym = brillouinzone.get_pointgroup_symmetry();
    // and might need the Phonon Gamma table
    GammaTable pgt{GammaTable()};
    if (RotatesLike::Gamma == this->data().vectors().rotateslike()){
      pgt.construct(brillouinzone.get_lattice().star(), brillouinzone.add_time_reversal());
    }
    brille::Array2<T> vals2(vals);
    brille::Array2<S> vecs2(vecs);
    // actually perform the rotation to Q
    this->data().values().rotate_in_place(vals2, ir_q, pgt, psym, rot, invrot, nth);
    this->data().vectors().rotate_in_place(vecs2, ir_q, pgt, psym, rot, invrot, nth);
    // we're done so bundle the output
    return std::make_tuple(vals, vecs);
  }
};

}
#endif