from matplotlib.pylab import *

# Radial wave functions for the Hydrogen atom for l = 0
# u is the radius in units of the Bohr radius
# n is the radial quantum number

def Radial(n,u):
   if n == 1:
	z = (exp(-u))
   elif n == 2:
	z = (exp(-u/2.0)*(2.0-u))
   elif n == 3:
	z = (exp(-u/3.0)*(27.0-18.0*u+2.0*u**2))
   elif n == 4:
	z = (exp(-u/4.0)*(192.0-144.0*u+24.0*u**2-u**3))
   elif n == 5:
	z = (exp(-u/5.0)*(9375.0-7500.0*u+1500.0*u**2-100.0*u**3+2.0*u**4))
   else:
	z = 0
	print n, ' is not a valid value of n'
   return z;