TDDFTBSigmaVectorEvaluator.h

Go to the documentation of this file.

#ifndef SPARROW_TDDFTBSIGMAVECTOREVALUATOR_H
#define SPARROW_TDDFTBSIGMAVECTOREVALUATOR_H

#include <Sparrow/Implementations/Dftb/TimeDependent/LinearResponse/TDDFTBData.h>
#include <Sparrow/Implementations/TimeDependent/TimeDependentUtils.h>
#include <Utils/Math/IterativeDiagonalizer/SigmaVectorEvaluator.h>
#include <Utils/Scf/LcaoUtils/ElectronicOccupation.h>

namespace Scine {
namespace Sparrow {

template<Utils::Reference restrictedness>
class OrderedInput;

enum class TDDFTBType { TDDFTB, TDA };

template<Utils::Reference restrictedness>
class TDDFTBSigmaVectorEvaluator final : public Utils::SigmaVectorEvaluator {
 public:
  TDDFTBSigmaVectorEvaluator(std::shared_ptr<Eigen::MatrixXd> gammaMatrix, std::shared_ptr<Eigen::VectorXd> spinConstants,
                             const OrderedInput<restrictedness>& orderedInput,
                             Utils::SpinTransition spinBlock = Utils::SpinTransition::Singlet,
                             TDDFTBType type = TDDFTBType::TDDFTB);
  ~TDDFTBSigmaVectorEvaluator() final = default;

  auto evaluate(const Eigen::MatrixXd& guessVectors) const -> const Eigen::MatrixXd& final;

 private:
  void calculateAtomicEnergyWeightedTransitionCharges(const Eigen::MatrixXd& transitionCharges);
  auto calculateXBI(const Eigen::VectorXd& guessVector) const -> Eigen::MatrixXd;
  auto calculateYAI(const Eigen::VectorXd& XBI) const -> Eigen::MatrixXd;
  auto calculateAtomicContraction(const Eigen::MatrixXd& YAIMatrix) const -> Eigen::VectorXd;
  template<typename Derived, typename OtherDerived>
  void fillAdditionalSigmaMatrixTerms(const Eigen::MatrixBase<Derived>& sigmaBlock,
                                      const Eigen::MatrixBase<OtherDerived>& guessVector) const;
  void collapsed(int newSubspaceDimension) final;
  auto factor() const -> double;

  void check() const;
  const OrderedInput<restrictedness>& input_;
  std::shared_ptr<Eigen::MatrixXd> gammaMatrix_;
  std::shared_ptr<Eigen::VectorXd> spinConstantsVector_;
  const bool isTDA_;
  Utils::SpinTransition spinBlock_{Utils::SpinTransition::Singlet};
  Eigen::MatrixXd energyWeightedAtomicTransitionCharges_;
  // Caching variable declared mutable in order not to influence the API design.
  mutable Eigen::MatrixXd currentSigmaMatrix_;
};

template<>
inline auto TDDFTBSigmaVectorEvaluator<Utils::Reference::Restricted>::factor() const -> double {
  return isTDA_ ? 2.0 : 4.0;
}
template<>
inline auto TDDFTBSigmaVectorEvaluator<Utils::Reference::Unrestricted>::factor() const -> double {
  return isTDA_ ? 1.0 : 2.0;
}
} // namespace Sparrow
} // namespace Scine

#endif // SPARROW_TDDFTBSIGMAVECTOREVALUATOR_H