[gmx-users] rlist

[Anton Feenstra]

Alan Wilter Sousa da Silva wrote:

> Cut-off and rlist is still a cloudy matter to me.

OK, let's try to shed some light:

- every nstlist steps, the neighborlist is updated. Only atom pairs 
within rlist get into the neigborlist.
- during neighborlist update, all 'long-range' (i.e. beyond rlist) 
interactions are calculated as well. This can be long-range cut-off 
(i.e., VdW up to rvdw and either Coulomb up to rcoul, or Coulomb by Ewald).
- every step, all interactions of atom pairs in the neighborlist (i.e., 
up to rlist) are calculated.

Does this help you?

> For instance, now I want Coulomb cut-off set 18 Angs. with Shift and vdW
> set 12 Angs with Cut-off, however rlist must be greater than rcoul and
> smaller than rvdW. How can I cope with that?

No, rlist need not be larger than rcoul. But, there have been issues 
with grompp not recognizing valid combinations of cut-off settings. 
Search the list...


-- 
Groetjes,

Anton

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|  _   _  ___,| K. Anton Feenstra                                     |
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