Limits which atoms will be plotted in the X-window by their scaled coordinates.
Also affects which atoms will be exported to the Atomeye .cfg file.

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Format: <tt>plot_limits = [ <i>enable sxmin sxmax symin symax szmin szmax</i> ] </tt>

<p>
If <tt><i>enable</i> == 1</tt>, the only atoms whose scaled coordinates falls within
the limits defined by the subsequent parameters are plotted (or exported).
