[gmx-users] More than one settle type.

[Mark Abraham]

On 11/02/2011 2:50 PM, Sikandar Mashayak wrote:
> Hi
>
> I am performing SPC/E water simulation where I want to fix location of 
> one water molecule and let others move. To do that I have defined two 
> groups with name SOL0 and SOL, where SOL0 has just one water molecule 
> and SOL grp contains all others. In .mdp file I define freezegrps as 
> SOL0 . When I do the simulation by mdrun I get error that "More than 
> one settle type.". I understand this means, I can not have two 
> molecules with [settle] constraints, I will have define [constraint] 
> for one SPC/E molecule explicitly. Can anyone please suggest me how to 
> do it?

I think you haven't quite understood the error, but I haven't got enough 
information to be sure. The error says that your topology cannot specify 
two molecule *types* with [ settle ] blocks. Where you say "groups" 
above, I think you mean "molecule blocks". The former are specified in 
an index file (and generated by default if no index file is used), and 
the latter in the [ molecules ] section of your topology. The two are 
unrelated. See this thread from just a fortnight ago 
http://lists.gromacs.org/pipermail/gmx-users/2011-January/057966.html. 
Searching for answers first before emailing is often educational :-).

Mark