[gmx-users] The Cut-off for coulombtype heat up the water system?

[Mark Abraham]

Chih-Ying Lin wrote:
> Hi
> People conclude that the heating up is normal by using a plain cut-off.
> So, how to fix the problem?

0. Do more background reading. :-)

> 1. From Berk => use multiple groups.
>     => how  ???
>     => I have been thinking that it is better to group the molecule
>     => such as: protein , non-protein
> 
> 2. change the coulombtype without the coulomb cut-off rcoulomb ?
>     => such as PME, PPPM ?
>     => what's the suggestion about this?
> 
> 3. Normally, how do people fix this problem?

These days, PME will tend to be the easiest to defend in a publication. 
You will have lower heating problems with various modified forms of 
cut-offs and/or longer cut-offs, but then you have the problem of 
justifying the use of the force field, which was probably parametrized 
for some other coulomb scheme.

Mark