  We present a method based on graph theory for evaluation of the inelastic
propensity rules for molecules exhibiting complete destructive quantum
interference in their elastic transmission. The method uses an extended
adjacency matrix corresponding to the structural graph of the molecule for
calculating the Green function between the sites with attached electrodes and
consequently states the corresponding conditions the electron-vibration
coupling matrix must meet for the observation of an inelastic signal between
the terminals. The method can be fully automated and we provide a functional
website running a code using Wolfram Mathematica, which returns a graphical
depiction of destructive quantum interference configurations together with the
associated inelastic propensity rules for a wide class of molecules.
