This presentation displays differences between "harmonic oscillator" and "Morse" potential energy functions and the resulting vibrational energies. This plot was used as an illustration in a Physical Chemistry course. The graph combines four data sets that have been assigned different colors and line types, resulting in a clear presentation of the differences between the two models. The line colors and types are identified in the legend box on the top right corner. The energy levels of the oscillators have been labeled by associating the energy values with label columns in the worksheets. A text box has been added to state the potential equations and the parameter values.