BEGIN_PROVIDER [ integer, shell_prim_num_max ]
 implicit none
 BEGIN_DOC
 ! Max number of primitives.
 END_DOC
 shell_prim_num_max = maxval(shell_prim_num)
END_PROVIDER

BEGIN_PROVIDER [ double precision, prim_normalization_factor , (prim_num) ]
  implicit none
  BEGIN_DOC
  ! Number of primitives per |AO|
  END_DOC

  logical                        :: has
  PROVIDE ezfio_filename
  if (mpi_master) then
    if (size(prim_normalization_factor) == 0) return

    call ezfio_has_basis_prim_normalization_factor(has)
    if (has) then
      write(6,'(A)') '.. >>>>> [ IO READ: prim_normalization_factor ] <<<<< ..'
      call ezfio_get_basis_prim_normalization_factor(prim_normalization_factor)
    else

      double precision               :: norm,overlap_x,overlap_y,overlap_z,C_A(3), c
      integer                        :: l, powA(3), nz
      integer                        :: i,j,k
      nz=100
      C_A(1) = 0.d0
      C_A(2) = 0.d0
      C_A(3) = 0.d0

      do i=1,shell_num

        powA(1) = shell_ang_mom(i)
        powA(2) = 0
        powA(3) = 0

        do k=1, prim_num
          if (shell_index(k) /= i) cycle
            call overlap_gaussian_xyz(C_A,C_A,prim_expo(k),prim_expo(k), &
              powA,powA,overlap_x,overlap_y,overlap_z,norm,nz)
            prim_normalization_factor(k) = 1.d0/dsqrt(norm)
        enddo
      enddo


    endif
  endif
  IRP_IF MPI_DEBUG
  print *,  irp_here, mpi_rank
  call MPI_BARRIER(MPI_COMM_WORLD, ierr)
  IRP_ENDIF
  IRP_IF MPI
  include 'mpif.h'
  integer                        :: ierr
  call MPI_BCAST( prim_normalization_factor, (prim_num), MPI_DOUBLE_PRECISION, 0, MPI_COMM_WORLD, ierr)
  if (ierr /= MPI_SUCCESS) then
    stop 'Unable to read prim_normalization_factor with MPI'
  endif
  IRP_ENDIF

  call write_time(6)

END_PROVIDER

 BEGIN_PROVIDER [ double precision, shell_coef , (shell_num, shell_prim_num_max) ]
&BEGIN_PROVIDER [ double precision, shell_expo , (shell_num, shell_prim_num_max) ]
  implicit none
  BEGIN_DOC
! Primitive coefficients and exponents for each shell.
  END_DOC

  integer :: i, idx
  integer :: count(shell_num)

  count(:) = 0
  do i=1, prim_num
    idx = shell_index(i)
    count(idx) += 1
    shell_coef(idx, count(idx)) = prim_coef(i)
    shell_expo(idx, count(idx)) = prim_expo(i)
  end do
END_PROVIDER


 BEGIN_PROVIDER [ double precision, shell_coef_normalized, (shell_num,shell_prim_num_max) ]
&BEGIN_PROVIDER [ double precision, shell_normalization_factor, (shell_num) ]
  implicit none
  BEGIN_DOC
  ! Coefficients including the |shell| normalization
  END_DOC
  logical                        :: has
  PROVIDE ezfio_filename

  shell_normalization_factor(:) = 1.d0
  if (mpi_master) then
    if (size(shell_normalization_factor) == 0) return

    call ezfio_has_basis_shell_normalization_factor(has)
    if (has) then
      write(6,'(A)') '.. >>>>> [ IO READ: shell_normalization_factor ] <<<<< ..'
      call ezfio_get_basis_shell_normalization_factor(shell_normalization_factor)
    endif
  endif
  IRP_IF MPI_DEBUG
  print *,  irp_here, mpi_rank
  call MPI_BARRIER(MPI_COMM_WORLD, ierr)
  IRP_ENDIF
  IRP_IF MPI
  include 'mpif.h'
  integer                        :: ierr
  call MPI_BCAST( shell_normalization_factor, (shell_num), MPI_DOUBLE_PRECISION, 0, MPI_COMM_WORLD, ierr)
  if (ierr /= MPI_SUCCESS) then
    stop 'Unable to read shell_normalization_factor with MPI'
  endif
  IRP_ENDIF

  call write_time(6)
  double precision               :: norm,overlap_x,overlap_y,overlap_z,C_A(3), c
  integer                        :: l, powA(3), nz
  integer                        :: i,j,k
  nz=100
  C_A = 0.d0
  powA = 0
  shell_coef_normalized = 0.d0

  do i=1,shell_num

    powA(1) = shell_ang_mom(i)

    ! Normalization of the primitives
    if (primitives_normalized) then
      do j=1,shell_prim_num(i)
        call overlap_gaussian_xyz(C_A,C_A,shell_expo(i,j),shell_expo(i,j), &
           powA,powA,overlap_x,overlap_y,overlap_z,norm,nz)
        shell_coef_normalized(i,j) = shell_coef(i,j)/dsqrt(norm)
      enddo
    else
      do j=1,shell_prim_num(i)
        shell_coef_normalized(i,j) = shell_coef(i,j)
      enddo
    endif

    ! Normalization of the contracted basis functions
    norm = 0.d0
    do j=1,shell_prim_num(i)
      do k=1,shell_prim_num(i)
        call overlap_gaussian_xyz(C_A,C_A,shell_expo(i,j),shell_expo(i,k),powA,powA,overlap_x,overlap_y,overlap_z,c,nz)
        norm = norm+c*shell_coef_normalized(i,j)*shell_coef_normalized(i,k)
      enddo
    enddo
    shell_normalization_factor(i) *= 1.d0/dsqrt(norm)
  enddo
END_PROVIDER