The mathematical details of the deformation parameters are as follows. Considering the success of the nuclear liquid drop model, in which the nucleus is taken to be an incompressible fluid, the harmonic oscillator frequencies are constrained so that ω ω z ω ω ⊥ ⊥ 2 = ω ω 0 3 remains constant with deformation, preserving the volume of equipotential surfaces. Reproducing the observed density of nuclear matter requires ℏ ℏ ω ω 0 ≈ ≈ ( 42 MeV ) A − − 1 / 3 , where A is the mass number. The relation between δ and the anisotropy is ( ω ω ⊥ ⊥ / ω ω z ) 2 = ( 1 + 2 3 δ δ ) / ( 1 − − 4 3 δ δ ) , while the relation between δ and the axis ratio R = ω ω ⊥ ⊥ / ω ω z is δ δ = ( 3 / 2 ) ( R 2 − − 1 ) / ( 2 R 2 + 1 ) .