Three-dimensional /-deformed harmonic

Clemenger [42] has studied the effect of ellipsoidal deformations in alkali clusters with N less than 100, using a modified three-dimensional harmonic oscillator model. The model considers different oscillator frequencies along the z axis (taken as symmetry axis) and perpendicular to the z axis. The model Hamiltonian used by Clemenger also contains an anharmonic term. Its purpose is to flatten the bottom of the potential well and to make it to resemble a rounded square-well potential. 

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