(*Hybridization .  
              This particular hybrid orbital is a linear combination of the  
2  s  orbital (denoted as  s) and 2 
             p irbital (denotes as  px) :  
          h =  N (s + u px) .  If u = 
          0,  
we have a pure  2  
        s (first picture) . 
Other pictures show hybrids sp3,  
      sp2 and sp .  
          First we have the Slater orbitals for the carbon atom,  
then for the fluorine atom*) 

dzeta = 1.625
r = (Sqrt[(x^2) + (y^2)])
cz = Exp[-dzeta*r]
Ns = (Sqrt[dzeta^(5/(3 π))])
Np = (Sqrt[dzeta^(5/( π))])
px = Np x cz
s = Ns *r* cz
u = 0
h =  1/Sqrt[1 + u^2] (s + u px)
ContourPlot[h, {x, -5, 5}, {y, -5, 5}, 
      PlotPoints -> 61]
u = Sqrt[1]
hsp = 1/Sqrt[1 + u^2] (s + u px)
ContourPlot[hsp, {x, -5, 5}, {y, -5, 5}, 
      PlotPoints -> 61]
u = Sqrt[2]
hsp2 =  1/Sqrt[1 + u^2] (s + u px)
ContourPlot[hsp2, {x, -5, 5}, {y, -5, 5}, 
      PlotPoints -> 61]
u = Sqrt[3]
hsp3 =  1/Sqrt[1 + u^2] (s + u px)
ContourPlot[hsp3, {x, -5, 5}, {y, -5, 5}, 
      PlotPoints -> 61]
u = 1000. 
h =  1/Sqrt[1 + u^2] (s + u px)
ContourPlot[h, {x, -5, 5}, {y, -5, 5}, 
      PlotPoints -> 61]

dzeta = 2.60
r = (Sqrt[(x^2) + (y^2)])
cz = Exp[-dzeta*r]
Ns = (Sqrt[dzeta^(5/(3 π))])
Np = (Sqrt[dzeta^(5/( π))])
px = Np x cz
s = Ns *r* cz
u = 0
h =  1/Sqrt[1 + u^2] (s + u px)
ContourPlot[h, {x, -5, 5}, {y, -5, 5}, 
      PlotPoints -> 61]
u = Sqrt[1]
hsp = 1/Sqrt[1 + u^2] (s + u px)
ContourPlot[hsp, {x, -5, 5}, {y, -5, 5}, 
      PlotPoints -> 61]
u = Sqrt[2]
hsp2 =  1/Sqrt[1 + u^2] (s + u px)
ContourPlot[hsp2, {x, -5, 5}, {y, -5, 5}, 
      PlotPoints -> 61]
u = Sqrt[3]
hsp3 =  1/Sqrt[1 + u^2] (s + u px)
ContourPlot[hsp3, {x, -5, 5}, {y, -5, 5}, 
      PlotPoints -> 61]
u = 1000. 
h =  1/Sqrt[1 + u^2] (s + u px)
ContourPlot[h, {x, -5, 5}, {y, -5, 5}, 
      PlotPoints -> 61]