!
  !-----------------------------------------------------------------------
  subroutine h_psi ( psi, hpsi, g2kin, vr)
  !-----------------------------------------------------------------------
  !
  ! hpsi = H_k | psi >
  !
  use gspace
  use constants
  use parameters
  implicit none
  !
  real(kind=DP) :: psi (ngm), hpsi (ngm), g2kin(ngm)
  complex(kind=DP) :: vr (nr), psic (nr), rhoca(nr1,nr2,nr3)
  integer :: ig, ir, i, j, k
  !
  !
  ! FFT test
  !
  allocate ( rhoca (nr1, nr2, nr3) )
  !
  do i = 1, nr1
   do j = 1, nr2
    do k = 1, nr3
      ir = i + (j-1) * nr1 + (k-1) * nr1 * nr2
      rhoca (i, j, k) = float(i) 
      vr ( ir ) = rhoca (i, j, k) 
      write (16,'(3i5,f9.5)') i,j,k,real(rhoca (i, j, k))
    enddo
   end do
  end do
  !
  ! go to G space
  call cfft3 ( vr, nr1, nr2, nr3, -1)
  psic = czero
  do ig = 1, ngm
    psic ( ig ) = vr ( nl ( ig ) )  ! psic is in order of increasing |G|^2
  enddo
  !
  ! now back to R space
  do ig = 1, ngm
    vr ( nl ( ig ) ) = psic (ig)
  enddo
  call cfft3 ( vr, nr1, nr2, nr3,  1)
  !
  do i = 1, nr1
   do j = 1, nr2
    do k = 1, nr3
      ir = i + (j-1) * nr1 + (k-1) * nr1 * nr2
      rhoca (i, j, k) = vr (ir)
      write (6,'(3i5,f9.5)') i,j,k,real(rhoca (i, j, k))
    enddo
   end do
  end do
  !
  stop
  !
  return
  end subroutine h_psi
  !