Lippincott—Schroeder LS Potential

In these expressions, / (or/) are the bond lengths (or the harmonic force constants) of the unperturbed HA and H - B bonds. The data for the unperturbed H - B bond are not usually known. However, Lippincott and Schroeder introduced the approximation 

Lippincott and Schroeder expressed the repulsive term as a negative exponential and the electrostatic one as a negative power of the AB distance. Both these terms involve empirical constants. They were modified to reduce the number of constants and the following expression was obtained  

The first derivative of the potential expresses the parameter A as a function of the repulsion constant b, and the set of parameters defined above 

Another important quantity in the LS potential is the force constant of the AB hydrogen bond. This can be obtained from the second derivative of the potential. 

The importance of this force constant results from its relation to the AB vibrational frequency 

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