[gmx-users] ns_type = simple not implemented?

[Erik Lindahl]

Amit Garg wrote:
> I have created RNA Go models and running them throuhg gromacs 3.1.4
> 
> In my mdp file I specify ns_type = simple but grompp complains the
> algorithm is not implemented.
> 
> Another installation of gromacs in my lab has the same problem so I am
> wondering if a) this is a bug or b) I am missing some files

I would guess the error message you're getting is that we haven't 
implemented the 'simple' algorithm for twin-range neighborsearching. 
This is because 'simple' is extremely expensive (order N*N) and normally
you would only use it for reference.

If you have a periodic system, you should use 'grid' neighborsearching
instead.

If you are simulating in vacuuo, there's no water, so you won't really 
gain anything by having separate short/long range cutoffs....


Cheers,

Erik