[gmx-users] VDW Cut-off vs Switch with CHARMM force field

[Gianluca Interlandi]

Hi!

I am running explicit solvent simulations with the CHARMM force field 
implemented in gromacs 4.6.3. For VDW I have been using:

rlist    = 1.0
vdw-type = Cut-off
rvdw     = 1.0

in conjunction with PME and rcoulomb=1 for electrostatics.

I wonder whether it would be more accurate to use instead a switching 
function for VDW between 0.8 and 1.0 and a larger rlist:

rlist       = 1.2
vdw-type    = Switch
rvdw_switch = 0.8
rvdw        = 1.0

My question is: does switching between 0.8 and 1.0 generate less artifacts 
than abrupt truncation at 1.0 nm for VDW?

Thanks!

      Gianluca

-----------------------------------------------------
Gianluca Interlandi, PhD gianluca at u.washington.edu
                     http://artemide.bioeng.washington.edu/

Research Scientist at the Department of Bioengineering
at the University of Washington, Seattle WA U.S.A.
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