program qmcpack
  implicit none
  BEGIN_DOC
! Generates a file for CHAMP
  END_DOC

  integer :: i,j,k,l, istate

  read_wf = .True.
  TOUCH read_wf
  do j=1,ao_prim_num_max
    do i=1,ao_num
      ao_coef(i,j) = ao_coef(i,j) * ao_coef_normalization_factor(i)
    enddo
  enddo
  call ezfio_set_ao_basis_ao_coef(ao_coef)
  do j=1,mo_num
    do i=1,ao_num
      mo_coef(i,j) *= 1.d0/ao_coef_normalization_factor(i)
    enddo
  enddo
  call save_mos
  call system('rm '//trim(ezfio_filename)//'/mo_basis/ao_md5')
  call system('$QP_ROOT/src/champ/qp_convert.py '//trim(ezfio_filename))

  integer :: iunit
  integer, external :: getUnitAndOpen
  iunit = getUnitAndOpen(trim(ezfio_filename)//'.H','w')

  double precision, external :: diag_h_mat_elem
  write(iunit,*) N_states
  do istate=1,N_states
    write(iunit,*) istate, psi_energy_with_nucl_rep(istate)
  enddo
  write(iunit,*) N_det
  do k=1,N_det
    write(iunit,'(I10,X,F22.15)') k, diag_h_mat_elem(psi_det(1,1,k),N_int) + nuclear_repulsion
  enddo


  double precision :: F(N_states)
  integer(bit_kind), allocatable :: det(:,:,:)
  double precision , allocatable :: coef(:,:)
  integer :: ispin
  double precision :: norm(N_states), hij
  allocate(det(N_int,2,N_det), coef(N_det,N_states))
  do j=1,mo_num
    do i=1,j-1
      do ispin=1,2
        call build_singly_excited_wavefunction(j,i,1,det,coef)
        F = 0.d0
        do istate=1,N_states
          norm(istate) = 0.d0
          do k=1,N_det
            norm(istate) = norm(istate) + coef(k,istate) * coef(k,istate)
          enddo
          if (norm(istate) > 0.d0) then
            norm(istate) = (1.d0/dsqrt(norm(istate)))
          endif
        enddo
        if (sum(norm(:)) > 0.d0) then
          
          do istate = 1,N_states
            coef(:,istate) = coef(:,istate) * norm(istate)
          enddo
          !$OMP PARALLEL DO DEFAULT(SHARED) PRIVATE(i,j,istate,hij) REDUCTION(+:F)
          do k=1,N_det
            if (sum(coef(k,:)*coef(k,:))==0.d0) cycle
            call i_H_j(det(1,1,k), det(1,1,k), N_int, hij)
            do istate=1,N_states
              F(istate) = F(istate) + hij*coef(k,istate)*coef(k,istate)
            enddo
            do l=1,k-1
              if (sum(coef(l,:)*coef(l,:))==0.d0) cycle
              call i_H_j(det(1,1,k), det(1,1,l), N_int, hij)
              do istate=1,N_states
                F(istate) = F(istate) + 2.d0*hij*coef(k,istate)*coef(l,istate)
              enddo
            enddo
          enddo
          !$OMP END PARALLEL DO
          F(:) = F(:) - psi_energy(:)
        endif
        do istate=1,N_states
          write(iunit,'(I4,X,I4,X,I1,X,I3,X,F22.15)') i, j, ispin, istate, F(istate) 
        enddo
      enddo
    enddo
  enddo

  deallocate(det,coef)

  close(iunit)

end