An n-body potential is constructed for the Cu-Ti-Hf ternary metal system under a recently proposed formalism named long-range empirical potential. Applying the proven relevant Cu-Ti-Hf potential, molecular dynamics simulations are carried out using solid solution model to compare the relative stability of the crystalline solid solution versus its disordered counterpart as a function of solute concentration. The simulation results not only reveal that the physical origin of the crystal-to-amorphous transition is the collapse of the crystalline lattice, while the solute atoms exceed the critical value, but also predict a region in the composition triangle energetically favored for the Cu-Ti-Hf ternary metallic glass formation. Interestingly, the prediction directly from the n-body potential is supported by the experimental observations and is in accordance with the so-called structural difference rule.