qp_plugins_scemama/devel/qmcchem/qmc_e_curve.irp.f

program e_curve
  use bitmasks
  implicit none
  integer :: i,j,k, kk, nab, m, l
  double precision :: norm, E, hij, num, ci, cj
  integer, allocatable :: iorder(:)
  double precision , allocatable :: norm_sort(:)
  double precision :: e_0(N_states)
  PROVIDE mo_two_e_integrals_in_map mo_one_e_integrals

  nab = n_det_alpha_unique+n_det_beta_unique
  allocate ( norm_sort(0:nab), iorder(0:nab) )

  double precision, allocatable  :: u_t(:,:), v_t(:,:), s_t(:,:)
  double precision, allocatable  :: u_0(:,:), v_0(:,:)


  norm_sort(0) = 0.d0
  iorder(0) = 0
  do i=1,n_det_alpha_unique
   norm_sort(i) = det_alpha_norm(i)
   iorder(i) = i
  enddo

  do i=1,n_det_beta_unique
   norm_sort(i+n_det_alpha_unique) = det_beta_norm(i)
   iorder(i+n_det_alpha_unique) = -i
  enddo

  call dsort(norm_sort(1),iorder(1),nab)

  if (.not.read_wf) then
    stop 'Please set read_wf to true'
  endif

  PROVIDE psi_bilinear_matrix_values nuclear_repulsion

  print *,  ''
  print *,  '=============================='
  print *,  'Energies at different cut-offs'
  print *,  '=============================='
  print *,  ''
  print *,  '=========================================================='
  print '(A8,2X,A8,2X,A12,2X,A10,2X,A12)',  'Thresh.', 'Ndet', 'Cost', 'Norm', 'E'
  print *,  '=========================================================='
  double precision :: thresh
  integer(bit_kind), allocatable :: det_i(:,:), det_j(:,:)
  integer :: na, nb
  thresh = 1.d-10
  na = n_det_alpha_unique
  nb = n_det_beta_unique
  do j=0,nab
    i = iorder(j)
    if (i<0) then
      nb -= 1
      do k=1,n_det
        if (psi_bilinear_matrix_columns(k) == -i) then
          psi_bilinear_matrix_values(k,1) = 0.d0
        endif
      enddo
    else
      na -= 1
      do k=1,n_det
        if (psi_bilinear_matrix_rows(k) ==  i) then
          psi_bilinear_matrix_values(k,1) = 0.d0
        endif
      enddo
    endif
    if (thresh > norm_sort(j)) then
      cycle
    endif

    do k=1,N_states
      psi_coef(1:N_det,k) = psi_bilinear_matrix_values(1:N_det,k)
      call dset_order(psi_coef(1,k),psi_bilinear_matrix_order_reverse,N_det)
    enddo
    TOUCH psi_det psi_coef

    m = 0
    do k=1,n_det
     if (psi_bilinear_matrix_values(k,1) /= 0.d0) then
      m = m+1
     endif
    enddo

    if (m == 0) then
       exit
    endif
    E = E_0(1) + nuclear_repulsion

    double precision :: cost0, cost
    cost0 = elec_alpha_num**3 + elec_beta_num**3
    cost = (na-1) * elec_alpha_num**2 + &
           (nb-1) * elec_beta_num**2 + &
            elec_alpha_num**3 + elec_beta_num**3
    cost = cost/cost0

    double precision :: u_dot_u
    norm = dsqrt(u_dot_u(psi_coef(1,1),N_det))
    print '(E9.1,2X,I8,2X,F10.2,2X,F10.8,2X,F15.10)',  thresh, m, &
      cost,  norm, psi_energy(1)
    thresh = thresh * dsqrt(10.d0)
  enddo
  print *,  '=========================================================='

  deallocate (iorder, norm_sort)
end