"fix rigid" NPT stationary hack

For some reason, this interesting (I think) discussion on "fix rigid"
never made it to the lammps mailing list. (I was not being modest. I
meant to post it there, but screwed up and forgot to include
lammps-users in the send-to field.) So I'm posting the entire thread
here.

There have been an obscene number of posts lately related to NPT and
immobilisation. Here are a few more. Cheers.
Andrew

fixrigid_test_npt.tar.gz (182 KB)