/**********************************************************

This software is part of J.-S. Caux's ABACUS library.

Copyright (c) J.-S. Caux.

-----------------------------------------------------------

File:  ABACUS_NRG.h

Purpose:  Declares NRG-related classes and functions.

***********************************************************/

#ifndef ABACUS_NRG_H
#define ABACUS_NRG_H

#include "ABACUS.h"

namespace ABACUS {

  DP K_Weight_integrand (Vect_DP args);  // weighing function for state selection

  void Select_States_for_NRG (DP c_int, DP L, int N, int iKmin, int iKmax, int Nstates_required,
			      bool symmetric_states, int iKmod,
			      int weighing_option, Vect<std::complex <DP> >& FT_of_potential);

  void Build_DFF_Matrix_Block_for_NRG (DP c_int, DP L, int N, int iKmin, int iKmax, int Nstates_required,
				       bool symmetric_states, int iKmod, int weighing_option,
				       int label_left_begin, int label_left_end, int label_right_begin, int label_right_end,
				       int block_option, DP* DFF_block_1, DP* DFF_block_2, Vect_DP Kweight);

}

#endif