program test_3d
 implicit none
 integer :: i,npt
 double precision :: dx,domain,x_min,x,step_function_becke
 domain = 5.d0
 npt = 100
 dx = domain/dble(npt)
 x_min = -0.5d0 * domain
 x = x_min
 do i = 1, npt
  write(33,*)x,step_function_becke(x)
  x += dx
 enddo

end