[gmx-users] ERROR: Twin-range neighbour searching (NS) with simple NS algorithm notimplemented

[Anton Feenstra]

Mehmet Suezen wrote:
> 
> Hi,
> 
> What may cause above error? As far as I understant from the manual
> following settings would be a legal.
> (ERROR:Twin-range neighbour searching (NS) with simple NS algorithm not
> implemented)
> 
> ; Neighbor Searching
> nstlist=0       ; frequency of constructing list
> ns_type=Simple  ; construction method
> pbc=no          ; periodicity in the system
> rlist=0.5       ; cutoff distance in the short-range neighborlist
> 
> ; Electrostatics and VdW
> coulombtype=Cut-off     ; cut-off
> rcoulomb=15             ; cut-off
> vdwtype=Cut-off         ; vdw cut_off
> rvdw=0.55               ; pair pot. cut-off
> DispCorr=no             ; dispersion correction

Selecting rlist!=rvdw or rlist!=rcoulomb (you have both!) will
(obviously?) get you a twin-range setup. As the message says, that
is not implemented. AFAI understand, that is not impossible, in fact
it would be almost trivial to implement, but it would add another 
combinatorial increment to the number of different inner-loop types 
that we already have (ask Erik Lindahl how much we like that!)...

By the way, do you really want a coulomb cut-off of 15 (!) nanometer,
or did you have 15 Angstrom in mind (i.e. 1.5 nm)?

-- 
Groetjes,

Anton
 ________ __________________________________________________________
|        | Anton Feenstra                                           |
| .      | Dept. of Pharmacochemistry - Free University Amsterdam   |
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