[gmx-developers] Re: Bug in distance restraint code?

[K.A. Feenstra]

Michael Patra wrote:
> 
> Hello!
> 
> I have encountered a problem with using distance restraints as specified in the
> [ distance_restraints ] section. From my analysis my "educated guess" is that
> this problem becomes relevant if two parts of a molecule are only connected by
> a distance restraint but not by a normal bond, and one part wraps over a period
> boundary.

[...snip...]
That is why distance restraints (as far as I am aware) are only
possible inside one molecule, i.e. it is in fact a special type
of bonded interaction. So the problem you describe could not
occur in an actual topology. However, it is desirable to be
able to specify distance restraints between molecules also, so
there will probably be a modification of the code at some point
to make that possible, which will also have to consider this
issue. Thanks anyway!

> If needed I can supply a (very large, 7000 atoms) test case.

We start calling things large at about 100,000... ;-)


P.S. We'd prefer if you send these type of messages to 
the developers mailinglist (gmx-developers at gromacs.org).


--Groetjes,

Anton