(*The potential energy for the rotating anharmonic oscillator. For  J=0 the potential is of the  Lennard-Jones type  
EPS (((((R0/R)))^12)-2 ((((R0/R)))^6)), where EPS denotes the well depth, and R0 stands for the equilibrium distance.
If the oscillators is rotationallyexcited, the shape of the potential energy changes qualitatively - a hump appears.
 The hump may cause the resonance states to appear *)
x1=3.5
x2=10.
EPS=6.
R0=4.
J=0
B=((627.7 J (J+1))/(2 920))
Plot[EPS (((((R0/R)))^12)-2 ((((R0/R)))^6))+(B/(R^2)),{R,x1,x2}]
J=10
B=((627.7 J (J+1))/(2 920))
Plot[EPS (((((R0/R)))^12)-2 ((((R0/R)))^6))+(B/(R^2)),{R,x1,x2}]
J=15
B=((627.7 J (J+1))/(2 920))
Plot[EPS (((((R0/R)))^12)-2 ((((R0/R)))^6))+(B/(R^2)),{R,x1,x2}]
J=20
B=((627.7 J (J+1))/(2 920))
Plot[EPS (((((R0/R)))^12)-2 ((((R0/R)))^6))+(B/(R^2)),{R,x1,x2}]