Write the current atomic configuration in the intermediate .cn file whose
name is specified by <tt>intercnfile</tt> and <tt>filecounter</tt>.  Usually
this is command is not called directly by the user.  Instead, it is called periodically
in MD simulation <tt>run</tt> if <tt>savecn = 1</tt>.

<p>
Also see <tt>openintercnfile</tt>.


