there are a few ways to do this that i've used. the most
straightforward way in my opinion, though, is to just adjust the
restraint_wt parameter. 1 is pretty standard, when i really don't
want something to move i'll use something like 8.0. here's an
example input:
Stage 1 heating of system from 0 to 50K
&cntrl
imin=0, irest=0, ntx=1,
nstlim=10000, dt=0.0005,
ntc=2, ntf=2,
ntt=1, tautp=1.0,
tempi=0.0, temp0=50.0,
ntpr=50, ntwx=50,
ntb=0, igb=1,
cut=999.,rgbmax=999.
ntr=1, restraint_wt=1.0,
restraintmask=':1-15, 28, 29, 30-45, 57,58, 59-74, 86, 87, 88-103,
115-116',
/
also, you can use the nmropt options to adjust the "stiffness" of
your restraints over time, which is more involved, but see the
section of the manual starting on p113 to look into that. it winds
up getting pretty tricky, but is certainly doable. you can, for
example, define a given distance that an atom can move penalty-free
and have it only start to pull it back to the reference structure
once it's reached a certain distance.
justin
On Jul 9, 2005, at 10:24 AM, Karthikeyan Pasupathy wrote:
> Is there any way by which one can define a position restraint with
> specific stiffness ??
>
> thank you!
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Received on Sun Jul 10 2005 - 01:53:00 PDT
