First, the fix adapt command is relatively new. So you can't use
it in the May 2008 version. But you can use the soft potential
to push atoms off each other. If things blow up after you do
this, they you likely didn't push them far enough off each other
or do it slowly enough. If you get high energies/pressures when
you turn off the soft and turn on LJ, then you didn't push
off enough.
Steve