a_ext_data Subroutine

  subroutine a_ext_data (A_ext_old, A_ext_new)
!      this routine returns current and previous A_ext vectors
    use theta_grid, only: ntgrid
    implicit none
    complex, dimension (-ntgrid:,:,:), intent(out) :: A_ext_old, A_ext_new

    if (.not. allocated(apar_new)) then
       A_ext_old = 0.
       A_ext_new = 0.
       return
    else
       A_ext_old = apar_old
       A_ext_new = apar_new
    end if

  end subroutine a_ext_data