Re: Reply to "MOPAC6.0 geometry optimization"

["DOUGLAS A. SMITH" <FAX0236 at.at uoft02.utoledo.edu>]

The default minimization routine in both MOPAC 5.0 and 6.0 is BFGS.  DFP
 has
 been discounted as a tremendously useful method.  MOPAC 6.0 also has
 eigenvector following (EF), which was not in 5.0.
 Your comment concerning the necessity to check that all optimization methods
 etc. are the same is salient.
 I don't believe that the isomer possibility is too viable.  We have done
 enough tests to believe that while you do find a stationary point at higher
 energy, it is typically very unrealistic as far as real chemistry (at least
 for our systems).
 Doug Smith