Table 3.

Top 12 descriptors as selected by the Random Forest mean decrease in Gini importance measurement.

Rank	Descriptor	Category
1	exch. eng. + e-e rep. for a C-N bond	Quantum-Chemical
2	Max resonance energy for a C-C bond	Quantum-Chemical
3	Molecular volume / XYZ Box	Geometrical
4	Min (>0.1) bond order of a C atom	Quantum-Chemical
5	Max total interaction for a C-C bond	Quantum-Chemical
6	Relative number of benzene rings	Constitutional
7	Average Information content (order 1)	Topological
8	exch. eng. + e-e rep. for a C-C bond	Quantum-Chemical
9	Max e-n attraction for a C-N bond	Quantum-Chemical
10	Relative number of C atoms	Constitutional
11	YZ Shadow/YZ Rectangle	Geometrical
12	Number of benzene rings	Constitutional