src/lib/chemistry/qc/lcao/df.h

//
// df.h
//
// Copyright (C) 2009 Edward Valeev
//
// Author: Edward Valeev <evaleev@vt.edu>
// Maintainer: EV
//
// This file is part of the SC Toolkit.
//
// The SC Toolkit is free software; you can redistribute it and/or modify
// it under the terms of the GNU Library General Public License as published by
// the Free Software Foundation; either version 2, or (at your option)
// any later version.
//
// The SC Toolkit 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 Library General Public License for more details.
//
// You should have received a copy of the GNU Library General Public License
// along with the SC Toolkit; see the file COPYING.LIB.  If not, write to
// the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
//
// The U.S. Government is granted a limited license as per AL 91-7.
//


#ifndef _mpqc_src_lib_chemistry_qc_df_df_h
#define _mpqc_src_lib_chemistry_qc_df_df_h

#include <util/state/state.h>
#include <util/misc/compute.h>
#include <util/group/memory.h>
#include <math/scmat/result.h>
#include <chemistry/qc/basis/integral.h>
#include <chemistry/qc/lcao/tbint_runtime.h>

namespace sc {

  class OrbitalSpace;
  class DistArray4;

  class DensityFitting: virtual public SavableState {
    public:
      enum SolveMethod {
        SolveMethod_InverseCholesky = 0,
        SolveMethod_Cholesky = 1,
        SolveMethod_RefinedCholesky = 2,
        SolveMethod_InverseBunchKaufman = 3,
        SolveMethod_BunchKaufman = 4,
        SolveMethod_RefinedBunchKaufman = 5
      };

      typedef TwoBodyMOIntsRuntimeUnion23 MOIntsRuntime;

      ~DensityFitting();
      DensityFitting(const Ref<MOIntsRuntime>& rtime,
                     const std::string& kernel_key,
                     SolveMethod solver,
                     const Ref<OrbitalSpace>& space1,
                     const Ref<OrbitalSpace>& space2,
                     const Ref<GaussianBasisSet>& fitting_basis);
      DensityFitting(StateIn&);
      void save_data_state(StateOut&);

      const Ref<MOIntsRuntime>& runtime() const { return runtime_; }
      const Ref<Integral>& integral() const {
        return runtime()->factory()->integral();
      }
      const Ref<OrbitalSpace>& space1() const { return space1_; }
      const Ref<OrbitalSpace>& space2() const { return space2_; }
      const Ref<GaussianBasisSet>& fbasis() const { return fbasis_; }
      const std::string& kernel_key() const { return kernel_key_; }
      SolveMethod solver() const { return solver_; }
      const Ref<DistArray4>& C() const {
        return C_;
      }
      RefSCDimension product_dimension() const;

      virtual void compute();

    private:

      Ref<MOIntsRuntime> runtime_;
      Ref<GaussianBasisSet> fbasis_;
      Ref<OrbitalSpace> space1_;
      Ref<OrbitalSpace> space2_;
      std::string kernel_key_;
      SolveMethod solver_;

      bool evaluated_;

      static ClassDesc class_desc_;

    protected:

      Ref<DistArray4> C_;
      RefSymmSCMatrix kernel_;
      Ref<DistArray4> cC_;

      const RefSymmSCMatrix& kernel() const {
        return kernel_;
      }
      const Ref<DistArray4>& conjugateC() const {
        return cC_;
      }

  };

  class TransformedDensityFitting: public DensityFitting {
    public:
      typedef DensityFitting::MOIntsRuntime MOIntsRuntime;

      ~TransformedDensityFitting();
      TransformedDensityFitting(const Ref<MOIntsRuntime>& rtime,
                                const std::string& kernel_key,
                                SolveMethod solver,
                                const Ref<OrbitalSpace>& space1,
                                const Ref<OrbitalSpace>& space2,
                                const Ref<GaussianBasisSet>& fitting_basis,
                                const Ref<DistArray4>& mo1_ao2_df);
      TransformedDensityFitting(StateIn&);
      void save_data_state(StateOut&);

    private:

      Ref<DistArray4> mo1_ao2_df_;

      // overloads DensityFitting::compute()
      void compute();

      static ClassDesc class_desc_;

  };

  class PermutedDensityFitting: public DensityFitting {
    public:
      ~PermutedDensityFitting();
      PermutedDensityFitting(const Ref<DensityFitting>& df21);
      PermutedDensityFitting(const Ref<MOIntsRuntime>& rtime,
                             const std::string& kernel_key,
                             SolveMethod solver,
                             const Ref<OrbitalSpace>& space1,
                             const Ref<OrbitalSpace>& space2,
                             const Ref<GaussianBasisSet>& fitting_basis,
                             const Ref<DistArray4>& df21);
      PermutedDensityFitting(StateIn&);
      void save_data_state(StateOut&);

    private:
      Ref<DistArray4> df21_;

      // overloads DensityFitting::compute()
      void compute();

      static ClassDesc class_desc_;

  };

  namespace test {

    class BasisProductDecomposition: virtual public SavableState {
      public:
        ~BasisProductDecomposition();
        BasisProductDecomposition(const Ref<Integral>& integral, const Ref<
            GaussianBasisSet>& basis1, const Ref<GaussianBasisSet>& basis2);
        BasisProductDecomposition(StateIn&);
        void save_data_state(StateOut&);

        virtual const RefSCMatrix& C() const =0;

        const Ref<Integral>& integral() const {
          return integral_;
        }
        const Ref<GaussianBasisSet>& basis(unsigned int i) const {
          return basis_[i];
        }

        virtual void compute() =0;

      protected:
        const RefSCDimension& product_dimension() const {
          return pdim_;
        }

      private:
        RefSCDimension pdim_; //< basis product dimension

        Ref<Integral> integral_;
        Ref<GaussianBasisSet> basis_[2];

    };

    class DensityFitting: public BasisProductDecomposition {
      public:
        ~DensityFitting();
        DensityFitting(const Ref<Integral>& integral, const Ref<
            GaussianBasisSet>& basis1, const Ref<GaussianBasisSet>& basis2,
                       const Ref<GaussianBasisSet>& fitting_basis);
        DensityFitting(StateIn&);
        void save_data_state(StateOut&);

        const RefSCMatrix& C() const {
          return C_;
        }
        const RefSymmSCMatrix& kernel() const {
          return kernel_;
        }
        const RefSCMatrix& conjugateC() const {
          return cC_;
        }

        // implements BasisProductDecomposition::compute()
        void compute();

      private:
        RefSCMatrix C_;
        RefSymmSCMatrix kernel_;
        RefSCMatrix cC_;

        Ref<GaussianBasisSet> fbasis_;

    };

  } // end of namespace test

} // end of namespace sc

#endif // end of header guard

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