The integrated intensity of each band in a system corresponding to transitions between two electronic states of a diatomic molecule is proportional to the square of a matrix element that one can form according to wave mechanics by integration of electronic and vibrational wave functions over electronic and nuclear coordinates. This matrix element can be taken to be a product of a factor involving electronic wave functions and a factor that is the square of an integral of wave functions of vibrational states; this squared integral is called a Franck-Condon factor, and this worksheet enables estimation of this quantity using vibrational wave functions of either an harmonic oscillator or a Morse oscillator.