The Le Verrier-Faddeev-Frame method was added to JOELib2, which allows to calculate characteristic polynomials for general weighted graphs with user defined atom and bond labels.
For theoretical and application details see:
1. Trinajstic, N. Chemical Graph Theory CRC Press, Florida, U.S.A., 1992
2. Bonchev, D. & Rouvray, D.H. (ed.) Chemical Graph Theory: Introduction and Fundamentals Gordon and Breach Science Publishers, 1990.