interaction_3ph.h

#ifndef PH_INTERACTION_H
#define PH_INTERACTION_H
 
#include <chrono>
#include <cmath>
#include <complex>
#include <iomanip>
 
#include "common_kokkos.h"
#include "constants.h"
#include "crystal.h"
#include "eigen.h"
#include "points.h"
#include "utilities.h"
 
class Interaction3Ph {
private:
  Crystal &crystal_;
 
  // variables to be saved on the GPU
  DoubleView5D D3_k;
  ComplexView4D D3PlusCached_k, D3MinsCached_k;
  DoubleView2D cellPositions2_k, cellPositions3_k;
  DoubleView3D weights2_k, weights3_k;
 
  // dimensions
  int nr2, nr3, numAtoms, numBands;
 
  double getDeviceMemoryUsage();
 
public:
 
  Interaction3Ph(Crystal &crystal, Eigen::Tensor<double, 5> &D3,
                 Eigen::MatrixXd &cellPositions2,
                 Eigen::MatrixXd &cellPositions3,
                 Eigen::Tensor<double,3> &weights2,
                 Eigen::Tensor<double,3> &weights3);
 
  Interaction3Ph(const Interaction3Ph &that);
 
  Interaction3Ph &operator=(const Interaction3Ph &that);
 
  ~Interaction3Ph();
 
  std::tuple<std::vector<Eigen::Tensor<double, 3>>,
             std::vector<Eigen::Tensor<double, 3>>>
  getCouplingsSquared(const std::vector<Eigen::Vector3d> &q1s_e,
                      const Eigen::Vector3d &q2_e,
                      const std::vector<Eigen::MatrixXcd> &ev1s_e,
                      const Eigen::MatrixXcd &ev2_e,
                      const std::vector<Eigen::MatrixXcd> &ev3Pluss_e,
                      const std::vector<Eigen::MatrixXcd> &ev3Minss_e,
                      const std::vector<int> &nb1s_e, const int nb2,
                      const std::vector<int> &nb3Pluss_e,
                      std::vector<int> &nb3Minss_e);
 
  void cacheD3(const Eigen::Vector3d &q2_e);
 
  int estimateNumBatches(const int &nq1, const int &nb2);
};
 
#endif