Vibronic Spectroscopy: In the harmonic oscillator approximation, simulate the So-S1 absorption spectrum of a diatomic. The simulation should convey both the energies of the transitions, as well as the relative intensities (think about Franck-Condon factors). Input must include the force constants in the ground and excited states (remember this determines the steepness of the wells, as well as the vibrational energy separation in each state) and re, the internuclear bond distance, within each state. The shift in relative re will determine the Franck-Condon factors of each transition (think about how to compute constructive interference of two vibrational wavefunctions that may be shifted with respect to on another).
Output the simulated absorption spectrum on the GUI.