DFT stabilty, spin containation, and freq. with G98.

Dear CCL'ers,
 I am using DFTs (B3LYP and BP86) in G98 to do some
 calculations on sc-containing molecules/ions. I would
 like to get your helps to solve following problems:
 1. For some species, the wavefunctions are unstable.
 When I used "Stable=opt" to reoptimize the wf, I found
 sometimes the job was aborted because the search did
 not lower the energy significantly. (e.g. for ScH+,
 the B3LYP wf can be reoptimized, but BP86 wf
 reoptimization was aborted.) Do you have special
 techniques to deal with this kind problem?
 2. Sometimes the Stable=opt works well for some
 species with unstable wavefunctions. It can gave a
 lower energy, but the spin containation becomes even
 higher than the unstable wf. What's the problem?
 3. When I calculate frequency in compound job step
 after the stable=opt with guess=read and
 geom=checkpoint, I find the calculation still uses the
 unstable wf and gives athe higher energy in the
 output. What's the right way to calculate frequency by
 using the reoptimized wf?
 Thanks a lot in advance! I am looking forward to your
 replies.
 Best regards,
 Tim Guo
 Email: timguo99 { *at * } yahoo.com
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