[gmx-users] rlist, rcolumb, and rvdw

[Mohsen Ramezanpour]

Dear gromacs users,

Reading through mailing list I found a nice discussion on the relation
between rlist, rcolumb, and rvdw:

https://www.mail-archive.com/gmx-users@gromacs.org/msg08387.html

https://mailman-1.sys.kth.se/pipermail/gromacs.org_gmx-users/2011-February/058507.html

If I understood correctly,

rcoulomb < rlist and rvdw < rlist is the most accurate way,

and
rlist=rcoulomb=rvdw is the commonly used way for these parameters.

I was wondering what would be the case if I want to change the cut-offs?

For instance, to use charmm36 in Groamcs, it is recommended to use 1.0-1.2

as the cut-off for LJ, and rlist=rcoulomb=rvdw

However, this setting might not result in good behaviour for some
lipid bilayers.

Therefore, I want to check if other cut-offs works better in gromacs.

If I change "1.2 nm" to "A nm" for rvdw, do I need to change rcolumb and
rlist to A as well? i.e. rlist=rcolumb=rvdw=A?

I am using following parameters already:

cutoff-scheme           = Verlet
nstlist                       = 20
rlist                          = *1.2*
coulombtype             = *pme*
rcoulomb                  = *1.2*
vdwtype                   = Cut-off
vdw-modifier            = *Force-switch*
rvdw_switch             = *1.0*
rvdw                        = *1.2*

Thanks in advance for your comments
Cheers
Mohsen
-- 
*Rewards work better than punishment ...*