[no subject]



 Dear Ari,
 We did some semiempirical and ab initio calcs on similar systems a
 year or so ago (see "Modeling the Hydrogen Bond", ACS Symposium Series
 569,
 Doug Smith, editor, 1994, pages 269-276).  Actually, the whole volume
 is a good summary of H-bond modeling.
 For our imidazole/oxazole type systems, we found that AM1 gave really
 poor results.  In some cases, it even missed some H-bonds altogether
 as I recall.  When we did ab initio calcs, even including correlation,
 we found these H-bonds to be very strong indeed (among the strongest
 H-bonds), and this correlated well with experiment.
 Good luck.
 Doug Dudis
 Polymer Branch
 Wright Laboratory - Materials Directorate
 Dayton, Ohio USA
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