AMBER Archive (2002)

Subject: water box-nonperiodic

From: Cozmuta (ioana_at_wag.caltech.edu)
Date: Fri Aug 02 2002 - 22:14:35 CDT


Hi amber users,

I am trying to build a water box with one single ion (K, Cl or Na) in the
center. I am loading the TIP4P model box and use the addIons command to
add the one ion. I get the following message:
 addIons ttt K+ 1
K+ has a charge of 0.
Adding the ions anyway.
Adding 1 counter ions to "ttt" using 1A grid
addIons: No solute to add ions to

When I edit the structure the ion is not in the water box.
What is the correct way to build this? Is there an equivalent way in AMBER
to the MMFP module in Charmm (not to run PBC but impose restraint
potentials on the water molecules so that they do not escape from the
"box")?

Thank you,
Ioana