(*PRZYKLAD KORELACJI,  
      BRAKU KORELACJI I ANTYKORELACJI w funkcjach falowych atomu helu,  opis na str  .531 i 532 ksiazki*) 
a0 = (E^(-(Sqrt[(x^2) + (y^2)])))
HFA = a0
Plot3D[HFA, {x, -2. , 2. }, {y, -2. , 2. }, 
      PlotPoints -> 40]
b = (E^(-1))
HFB = b a0
Plot3D[HFB, {x, -2. , 2. }, {y, -2. , 2. }, 
      PlotPoints -> 40]
c0 = (E^(-((x^2) + (y^2))))
c1 = (E^(-((((x - 1))^2) + (y^2))))
CGA = c0 (E^(-2 ((x^2) + (y^2))))
CGB = 
      b c0 (E^(-2 ((((x - 1))^2) + (y^2))))
PCGA = c0 - CGA
PCGB = 
      b c0 (1 - (E^(-2 ((((x - 1))^2) + (y^2)))))
CZ1A = c0 (1 + (1/2) (Sqrt[(x^2) + (y^2)]))
CZ1B = b c0 (1 + (1/2) (Sqrt[(((x - 1))^2) + (y^2)]))
CZ2A = c0 (1 + 25 (Sqrt[(x^2) + (y^2)]))
CZ2B = b c0 (1 + 25 (Sqrt[(((x - 1))^2) + (y^2)]))
Plot3D[CGA, {x, -2. , 2. }, {y, -2. , 2. }, 
      PlotPoints -> 40]
Plot3D[CGB, {x, -2. , 2. }, {y, -2. , 2. }, 
      PlotPoints -> 40]
Plot3D[PCGA, {x, -2. , 2. }, {y, -2. , 2. }, 
      PlotPoints -> 40]
Plot3D[PCGB, {x, -2. , 2. }, {y, -2. , 2. }, 
      PlotPoints -> 40]
Plot3D[CZ1A, {x, -2. , 2. }, {y, -2. , 2. }, 
      PlotPoints -> 40]
Plot3D[CZ1B, {x, -2. , 2. }, {y, -2. , 2. }, 
      PlotPoints -> 40]
Plot3D[CZ2A, {x, -2. , 2. }, {y, -2. , 2. }, 
      PlotPoints -> 40]
Plot3D[CZ2B, {x, -2. , 2. }, {y, -2. , 2. }, 
      PlotPoints -> 40]