  The calculation of Franck-Condon factors between different one-dimensional
Morse potential eigenstates using a formula derived from the Wigner function is
discussed. Our numerical calculations using a very simple program written in
Mathematica is compared with other calculations. We show that our results have
a similar accuracy as the calculations performed with more sophisticated
methods. We discuss the extension of our method to include non-Condon effects
in the calculation.
