Ways to Reduce Search Space: Heuristics
- Careful design of the move generator so that
equivalent structures are not generated again:
CH3-CH2- vs. -CH2-CH3
- Rules that detect particular substructures in the mass spectrogram
predict some parts of the molecular structure; these parts are put on a
GOODLIST and are generated first.
Rule: M-44 is a high peak, and 44 is a high peak
- A BADLIST contains substructures which are
unstable or could not be present because their
signatures do not appear in the mass spectrogram:
H-C-N=O, O-O, S-S-S are forbidden substructures because they are unstable.
Any move which results in a BADLIST substructure
is immediately detected and eliminated, pruning
the whole search tree below that node.