[gmx-users] vdw-modifier in GROMACS 4.6.1.

[Chrisostomos Batistakis]

Dear all

I have started simulations with the GROMACS 4.6.1, but I am bit confused
with the application of the vdw-modifier. As far as I understand, in the
case of :

vdw-type= cut-off
vdw-modifier-Potential-Shift

the result will be a LJ potential shifted by a constant in order to be zero
at the cut-off distance. But in the case where:

vdw-type= Switch
vdw-modifier-Potential-Shift

the Switch function already  modifies the potential and the forces in order
to smoothly go to zero between the rvdw-switch and rdvw distances..
What is then the role of the vdw-modifier in the latter case?

Thanks in advance
Tommy