Potential Energy Surfaces Using Algebraic Methods Based on Unitary Groups

Table 1

Force constants for H₂O obtained from the fit (118) using (a) the quantum mechanical connection (QM) given by (82), (b) the coherent states method (CS), and (c) the coherent state approach taking the harmonic limit 𝑁→∞.

Force constant	QM	CS	CS(𝑁→∞)
𝑓𝑟𝑟aJÅ^−2	8.0409	7.6389	8.0409
𝑓𝑟𝑟′aJÅ^−2	−0.1122	−0.1115	−0.1154