Re: [h5md-user] box and observables

[Peter Colberg]

On Tue, Sep 24, 2013 at 12:51:15PM -0400, Peter Colberg wrote:
> > So looking at this purely from the point of view of writing and
> > reading positions, a box group per subsystem is highly desirable.
> 
> For that specific case, yes, that would be desirable.

A different aspect to consider:

Suppose I wish to display the combined particle positions of two or
more subsystems in a visualization program. If each subsystem has its
own box copy, which box group does the reader read, and which box
groups are discarded? Does the reader need to verify that the box
information of all groups coincides?

As long as we can agree on a single physical box per H5MD root,
agreeing on a single box group to represent this data also avoids
this ambiguity.

Peter