Kinematic perturbation in the three-body problem

The mixed derivatives that appear in the three-body Schrödinger equation (when written in terms of interparticle distances) are treated as a perturbation. The following results are obtained: (a) B3㉥3B2, where Bn is the n body binding energy. (b) For the harmonic oscillator potential, the calculated binding energy falls within 3% of the exact one. Numerical results for attractive square well and exponential potentials are presented. NUCLEAR STRUCTURE Three body, Schrödinger equation, perturbation theory, binding energy.