Exhaustive isomer generation using the genetic algorithm
Building upon previous work, software that generates isomers from real-life constraints (large fragments, hybridisation states, etc.) is presented. The software is based on the genetic algorithm. Isomer generation seems exhaustive. Numerical analysis objections against floating-point approximations to real number-based topological Indices are delivered. Also described isa novel, integer-based, efficient way to discriminate between isomers by computing their "fingerprints". This also allows determination of topological equivalence classes. Results are compared with those from DENDRAL, MOLGEN+, AEGIS, CHEMICS, Hendrickson's SKEL_GEN and ESESOC. Omissions in DENDRAL's isomer lists are observed and illustrated. Comparison with SKEL_GEN and MOLGEN show small, explained discrepancies with Galvastructures for some very unsaturated molecules; perfect agreement is obtained in all other cases. The software used is available freely, to let readers replicate the results and test the method on the information of their choice.
isomer generation genetic algorithm topological equivalence classes galvastructures structural elucidation connectivity matrices