Program Listing for File cc.hpp

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#ifndef SEQUANT_DOMAIN_MBPT_MODELS_CC_HPP
#define SEQUANT_DOMAIN_MBPT_MODELS_CC_HPP

#include <SeQuant/core/op.hpp>
#include <SeQuant/domain/mbpt/op.hpp>
#include <SeQuant/domain/mbpt/vac_av.hpp>

#include <cstddef>
#include <limits>
#include <optional>
#include <vector>

namespace sequant {
class ExprPtr;
}

namespace sequant::mbpt {

class CC {
 public:
  enum class Ansatz {
    T,
    oT,
    U,
    oU
  };

  struct Options {
    Ansatz ansatz = Ansatz::T;
    bool screen = true;
    bool use_topology = true;
    std::optional<size_t> hbar_comm_rank = std::nullopt;
    std::optional<size_t> pertbar_comm_rank = std::nullopt;
  };

  explicit CC(size_t n);

  explicit CC(size_t n, const Options& opts);

  [[nodiscard]] Ansatz ansatz() const;

  [[nodiscard]] bool unitary() const;

  [[nodiscard]] bool screen() const;

  [[nodiscard]] bool use_topology() const;

  [[nodiscard]] std::vector<ExprPtr> t(
      size_t pmax = std::numeric_limits<size_t>::max(), size_t pmin = 0);

  [[nodiscard]] std::vector<ExprPtr> λ();

  // clang-format off
  // clang-format on
  [[nodiscard]] std::vector<ExprPtr> tʼ(
      size_t rank = 1, size_t order = 1,
      std::optional<size_t> nbatch = std::nullopt);

  // clang-format off
  // clang-format on
  [[nodiscard]] std::vector<ExprPtr> λʼ(
      size_t rank = 1, size_t order = 1,
      std::optional<size_t> nbatch = std::nullopt);

  [[nodiscard]] std::vector<ExprPtr> eom_r(nₚ np, nₕ nh);

  [[nodiscard]] std::vector<ExprPtr> eom_l(nₚ np, nₕ nh);

 private:
  size_t N;
  Ansatz ansatz_ = Ansatz::T;
  bool screen_ = true;
  bool use_topology_ = true;
  std::optional<size_t> hbar_comm_rank_ = std::nullopt;
  std::optional<size_t> pertbar_comm_rank_ = std::nullopt;

  auto ref_av(const ExprPtr& expr,
              const OpConnections<std::wstring>& op_connect =
                  default_op_connections()) const {
    return op::ref_av(expr, op_connect, this->use_topology(), this->screen());
  }
};  // class CC

}  // namespace sequant::mbpt

#endif  // SEQUANT_DOMAIN_MBPT_MODELS_CC_HPP